Elastomer polymer blends

ABSTRACT

The present invention relates to compositions comprising at least one elastomer and at least one plastic. The composition can be produced by preparing the elastomer and then blending it with the plastic. The composition can be subjected to an additional step of curing.

This application is a continuation of U.S. application Ser. No.07/321,367, filed 3/9/89, now abandoned, which is a divisionalapplication of Ser. No. 06/835,211, filed 3/3/86 now issued as U.S. Pat.No. 4,843,129.

BACKGROUND OF THE INVENTION

The following information pertains to related applications.

FIELD OF THE INVENTION

The invention relates to novel blends of elastomers and plasticcompositions, and to novel processes for producing such blends.

More specifically, the plastics which may be employed in these blendsinclude polypropylenes, polyethylenes, including high densitypolyethenes, low density polyethylenes, and linear low densitypolyethylenes, polystyrenes, polyvinyl chlorides, polycarbonates,polyamides (nylons), polyesters, polyphenylene oxides,ethylene/methylacrylate copolymers, polybutylenes, polyvinyl acetates,ethylene/vinyl acetate copolymers, polymethyl methacrylates,acrylonitrile-butadiene-styrenes, acetals, alkyds, acrylics, polyethylmethacrylates, and heteroblock propylene-ethylene copolymers. Alsosuitable are mixtures of two or more of such plastic compositions,especially mixtures of polypropylene and polyethylene, including highdensity polyethylene (HDPE), low density polyethylene (LDPE), and linearlow density polyethylene.

Among the suitable polypropylenes are those disclosed in Smith, Jr.(U.S. Pat. No. 4,059,651), Huff (U.S. Pat. No. 4,087,485), Fielding etal. (U.S. Pat. No. 4,087,486), Huff (U.S. Pat. No. 4,221,882), Smith,Jr. (U.S. Pat. No. 4,251,646), and Ross (U.S. Pat. No. 4,375,531), thedisclosures of which are hereby incorporated by reference thereto.

Suitable elastomers for use in the blend are the compositions disclosedin related U.S. Pat. Nos. 4,540,753 (Cozewith, et al.), 4,716,207,4,874,820, 4,786,697, 4,789,714, and 4,882,406.

BACKGROUND DESCRIPTION OF RELEVANT MATERIALS

For convenience, certain terms that are repeated throughout the presentspecification are defined below:

(a) Inter-CD defines the compositional variation, in terms of ethylenecontent, among polymer chains. It is expressed as the minimum deviation(analogous to a standard deviation) in terms of weight percent ethylenefrom the average ethylene composition for a given copolymer sampleneeded to include a given weight percent of the total copolymer samplewhich is obtained by excluding equal weight fractions from both ends ofthe distribution. The deviation need not be symmetrical. When expressedas a single number, for example 15% Inter-CD, it shall mean the largerof the positive or negative deviations. For example, for a Gaussiancompositional distribution, 95.5% of the polymer is within 20 wt. %ethylene of the mean if the standard deviation is 10%. The Inter-CD for95.5% wt. % of the polymer is 20 wt. % ethylene for such a sample.

(b) Intra-CD is the compositional variation, in terms of ethylene,within a copolymer chain. It is expressed as the minimum difference inweight (wt.) % ethylene that exists between two portions of a singlecopolymer chain, each portion comprising at least 5 weight % of thechain.

(c) Molecular weight distribution (MWD) is given a measure of the rangeof molecular weights within a given copolymer sample. It ischaracterized in terms of at least one of the ratios of weight averageto number average molecular weight, M_(w) /M_(n), and Z average toweight average molecular weight, M_(z) /M_(n), where ##EQU1##

Ni is the number of molecules of weight Mi.

Ethylene-propylene copolymers, particularly elastomers, are importantcommercial products. Two basic types of ethylene-propylene copolymersare commercially available. Ethylene-propylene copolymers (EPM) aresaturated compounds requiring vulcanization with free radical generatorssuch as organic peroxides. Ethylene-propylene terpolymers (EPDM) containa small amount of non-conjugated diolefin, such as dicyclopentadiene,1,4-hexadiene, or ethylidene norbornene, which provides sufficientunsaturation to permit vulcanization with sulfur. Such polymers thatinclude at least two monomers, i.e., EPM and EPDM, will hereinafter becollectively referred to as copolymers

These copolymers have outstanding resistance to weathering, good heataging properties and the ability to be compounded with large quantitiesof fillers and plasticizers, resulting in low cost compounds which areparticularly useful in automotive and industrial mechanical goodsapplications. Typical automotive uses are in tire sidewalls, innertubes, radiator and heater hose, vacuum tubing, weather stripping andsponge doorseals, and as Viscosity Index (V.I.) improvers forlubricating oil compositions. Typical mechanical goods uses are forappliance, industrial and garden hoses, both molded and extruded spongeparts, gaskets and seals, and conveyor belt covers. These copolymersalso find use in adhesives, appliance parts, as in hoses and gaskets,wire and cable, and plastics blending.

The efficiency of peroxide curing depends on composition. As theethylene level increases, it can be shown that the "chemical" crosslinksper peroxide molecule increase. Ethylene content also influences therheological and processing properties, because crystallinity, which actsas physical crosslinks, can be introduced. The crystallinity present atvery high ethylene contents may hinder processibility, and may make thecured product too "hard" at temperatures below the crystalline meltingpoint to be useful as a rubber.

As can be seen from the above, based on their respective properties, EPMand EPDM find many, varied uses. It is known that the properties of suchcopolymers which make them useful in a particular application are, inturn, determined by their composition and structure. For example, theultimate properties of an EPM or EPDM copolymer are determined by suchfactors as composition, compositional distribution, sequencedistribution, molecular weight, and molecular weight distribution (MWD).

It is well known that the breadth of the MWD can be characterized by theratios of various molecular weight averages. One of such averages is theratio of weight average to number average molecular weight (M_(w)/M_(n)). Another of the ratios is the Z average molecular weight toweight average molecular weight (M_(z) /M_(w)).

Copolymers of ethylene and at least one other alpha-olefin monomer,including EPM and EPDM polymers, which are intramolecularlyheterogeneous and intermolecularly homogenous, and which have a narrowMWD, characterized as at least one of M_(w) /M_(n) less than 2 and M_(z)/M_(w) less than 1.8, have improved properties in lubricating oil. Suchcopolymers are disclosed in Cozewith et al., which is incorporatedherein by reference. For convenience, such polymers are hereinafterreferred to as narrow MWD copolymers. Copolymers having MWD with bothM_(w) /M_(n) greater than or equal to 2 and M_(z) /M_(w) greater than orequal to 1.8 are hereinafter referred to as broad MWD copolymers.

It is generally recognized that the cure rate and physical properties ofcopolymers of ethylene and at least one other alpha-olefin monomer areimproved as MWD is narrowed. Narrow MWD polymers have superior cure andtensile strength characteristics over such polymers having broader MWD.However, the advantages in physical properties gained from having anarrow MWD are sometimes offset by the poorer processability of suchmaterials. They are often difficult to extrude, mill, or calendar.Nevertheless, is certain instances the narrow MWD copolymer isadvantageous in plastics blending.

As to milling behavior of EPM or EPDM copolymers, this property variesradically with MWD Narrow MWD copolymers crumble on a mill, whereasbroad MWD materials will band under conditions encountered in normalprocessing equipment. Broader MWD copolymer has a substantially lowerviscosity than narrower MWD polymer of the same weight average molecularweight.

Thus, there exists a continuing need for discovering polymers withunique properties and compositions. This is easily exemplified withreference to the area of blends of elastomers and plastics havingvarious utilities.

Plastic-elastomer blends comprising a discontinuous phase of theelastomer dispersed within a continuous phase of the plastic findvarious uses, such as in battery cases. For such blends, an intimatedispersion of the elastomer discontinuous phase within the plasticcomposition continuous phase is a desirable property.

Blends comprising cocontinuous phases of plastic and elastomer tend tohave greater impact strength than the pure plastic compositions, and areuseful in such products as automobile bumpers.

It is highly desirable in plastic-elastomer blends, particularly thecontinuous-discontinuous phases blends, to attain a higher Gardnerimpact strength without a corresponding lowering of knit line toughnessor stiffness.

U.S. Pat. No. 4,059,651 discloses a blend of 70-98 wt. % polypropylene,2-30 wt. % EPDM elastomer, and halogenated phenol adehyde resin presentin an amount of about 1-20 parts per 100 parts of elastomer. Theelastomer is disclosed as containing about 40-80 wt. % ethylene andabout 2-12 wt. % diene with the balance being propylene. The componentsare mixed by conventional techniques and heated at above the meltingpoint of the propylene, e.g., 300°-400° F. Alternatively, thehalogenated phenol aldehyde resin may first be mixed with thepolypropylene at these same temperatures, with the elastomer mixed inthereafter. After the mixtin and heating, the blend may be molded.

U.S. Pat. No. 4,087,485 to Huff discloses a blend comprising about 2-20%by weight ethylene-propylene copolymer elastomer, 70-90% by weightpolypropylene, and about 1-15% by weight LDPE. The elastomer may furtherinclude a non-conjugated diene. The blend may be prepared by mixing withconventional equipment at 350°-400° F. for about 4-7 minutes, withconventional agents employed for curing.

U.S. Pat. No. 4,088,714 to Huff discloses a blend comprising 40-90 wt. %EPR, EPM, or EPDM copolymer, 14-20 wt. % cross-linkable low densitypolyethyelene, and less than 50 wt. % isotactic polypropylene. Threeradical generating or cross-linking agents such organic peroxides areused to cross-link the elastomer and the cross-linkable low densitypolyethylene. Triallylcyanurate is employed to enhance the curing andincrease resiliency, tensile strength, and impact strength.

U.S. Pat. No. 4,221,882 to Huff discloses blends comprising 45-67%polypropylene, 30-45% polyethylene, and 3.5-11% ethylene-propylenecopolymer. The polypropylene and ethylene-propylene compolymer arepremixed by conventional means and heated to about 204° C. The pre-blendis then pelletized or powdered and mixed with virgin high densitypolyethylene, and melt-mixed as an extruder let down, normally at about204° C. The final blend is then employed for molding parts.

U.S. Pat. No. 4,251,646 to Smith, Jr. discloses a blend of 60-90% byweight polypropylene, 30-5% by weight thermoplastic crystallineheteroblock propylene-ethylene copolymer, and 30-5% ethylene-propylenecopolymer. The blends are processed by conventional techniques attemperatures above 200° C., are readily extrudable and moldable.

U.S. Pat. No. 4,375,531 to Ross discloses visbroken polymeric blendscomprising a first component selected from a group consisting of blockpropylene-ethylene copolymers, reactor-made intimate mixtures ofpolypropylene and randomly oriented copolymers of propylene andethylene, and blends of propylene and randomly oriented copolymers ofpropylene and ethylene, and a second component selected from the groupconsisting of low density polyethylene, ethylene-vinyl acetatecopolymer, acrylate-modified polyethylenes, high density polyethylenes,ethylene-propylene rubber (EPR or EPDM), and blends thereof. The methodfor producing the composition comprises first blending the components,and then visbreaking the resulting blend. The visbreaking may be carriedout in the presences of peroxide concentrations of 50-2,000 ppm, andmelt temperatures of 350°-550° F., in a single or twin screw extruder.Thermal visbreaking, at temperatures in excess of 550° F. and theabsence of free radial initiators and process or heat stabilizeradditives, can also be used.

"Structure and Properties of Rubber Modified Polypropylene ImpactBlends," F. C. Stehling, T. Huff, C. S. Speed, and G. Wissler, Journalof Applied Polymer Science, Vol. 26, pp. 2693-2711 (1981), discloses thedispersion of poly(ethylene-co-propylene) (PEP) rubber and high densitypolyethylene (HDPE) in polypropylene (PP) blends. Various PP-PEP blends,such as 90-10, 85-15, and 80-20 wt. % ratios, and PP-PEP-HDPE blendsincluding 80-10-10, 85-7.5-7.5, and 90-5-5 wt. % ratios, were studied.In such ratios, PEP was dispersed at a discontinuous phase within acontinuous phase of PP in the two component blends. In the threecomponent blends, a discontinuous phase of particles of PEP and HDPE wasdispersed within a continuous phase of PP; the particles of thediscontinuous phase comprised an interior region of HDPE surrounded byan outer layer of PEP.

None of these references discloses or suggests the use of the elastomercompositions disclosed in the Cozewith et al. patent or applications insuch plastic-elastomer blends.

SUMMARY OF THE INVENTION

It is, therefore, an object of the invention to provide and novel andimproved elastomer-plastic blends, utilizing the elastomer compositionsdisclosed in the Cozewith et al. patent and applications.

According to the invention, an elastomer-plastic composition is providedwhich comprises:

(a) at least one copolymer having at least M_(w) /M_(n) less than 2 anda M_(z) /M_(w) less than 1.8; and

(b) at least one plastic composition. Preferably, the at least onecopolymer has M_(w) /M_(n) less than 1.4, and M_(z) m_(w) less than 1.3.

The at least one copolymer may comprise ethylene and alpha-olefinmonomer. Preferably, the alpha-olefin monomer contains 3-18 carbonatoms. Most preferably, it is propylene.

Ninety-five (95) wt. % of the copolymer chains of the copolymer may havean ethylene composition that differs from its average weight percentethylene composition by not more than 15 wt. %, and at least twoportions of essentially each copolymer chain of the first copolymer,each portion comprising at least 5 wt. % of the chain, may differ incomposition from one another by at least about 5 wt. % ethylene.

The copolymer may be an ethylene propylene terpolymer, which maycomprise ethylene, propylene, and a non-conjugated diene selected fromthe group consisting of ethylidene norborene, 1,4-hexadiene,dicyclopentadiene, vinyl norbornene, methylene norbornene, and mixturesthereof.

The plastic composition may be a thermoplastic composition, and mayfurther be selected from a group consisting of polypropylenes,polyethylenes, ethylene/vinyl acetate copolymers, polyamides, polyphenyloxides, polycarbonates ethylene/methyl acrylate copolymers, polymethylmethacrylates, polyvinyl chlorides, acrylonitrile-butadiene-styrenes,polyethyl methacrylates, polystyrenes, polybutylenes, polyesters,acetals, alkyds, polyvinyl acetates, acrylics, and heteroblockpropylene-ethylene copolymers.

Preferably, the thermoplastic composition is polypropylene, or aheteroblock propylene-ethylene copolymer.

Where the thermoplastic composition is polypropylene, it preferablycomprises approximately 98-50% by weight of the composition of theinvention, with the at least one copolymer comprising approximately2-50% by weight of the composition.

Where the thermoplastic composition is the heteroblock copolymer, thiscopolymer preferably comprises approximately 98-50% by weight of thecomposition. This heteroblock copolymer preferably comprisesapproximately 50-98% by weight propylene block and approximately 2-50%by weight post block of ethylene and propylene. This post blockpreferably comprises 20-78% by weight ethylene.

The composition of the invention may include two or more plastics, suchas polyethylene and polypropylene.

In the composition in the invention, the one or more plasticcompositions may take the form of a continuous phase, and the one ormore copolymers may take the form of a discontinuous phase dispersedwithin this continuous phase.

In such an embodiment, such continuous phase is preferably polypropylenecomprising at least 90 wt. % of the composition, and the discontinuousphase is ethylene-propylene copolymer, ethylene-propylene terpolymer, ora combination thereof, and comprises approximately 10 wt. % or less ofthe composition.

The composition of the invention may further take the form of acontinuous phase comprising a first plastic composition, and adiscontinuous phase, dispersed within this continuous phase, comprisinga second plastic composition and at least one copolymer. In such anembodiment, the first plastic composition is preferably polypropylene,and the second plastic composition is preferably polyethylene; thecopolymer is preferably an ethylene-propylene copolymer, anethylene-propylene terpolymer, or mixtures thereof. Most preferably, thepolypropylene comprises at least 85 wt. % of the composition, thepolyethylene comprises approximately 5 wt. % or less of the composition,and the indicated copolymer or copolymers comprises approximately 10 wt.% or less of the composition.

The at least one copolymer of the composition of the invention maycomprise a plurality of copolymer chains, substantially each of whichcomprises a first segment, being in the form of one contiguous or aplurality of discontinuous segments, comprising a copolymer of ethyleneand an alpha-olefin; and a second segment comprising a copolymer ofethylene, an alpha-olefin, and a coupling agent, said second segmentconstituting less than 50% by weight of said copolymer chain and beingin the form of one contiguous segment or a plurality of discontinuoussegments. The coupling agent is cross-linkable under conditions which donot cross-link said first segment to any substantial extent. Preferably,this copolymer has at least one of M_(w) /M_(n) less than 2 and a M_(z)/M_(w) less than 1.8.

The indicated alpha-olefin may be propylene. The coupling agent may be aZiegler copolymerizable diene preferably selected from the groupconsisting of norbornadiene, vinyl norbornene, and butenyl norbornene.In the alternative, the coupling agent may be a cross-linkable dienepreferably selected from the group consisting of ENB, 1,4-hexadiene anddicyclopentadiene.

The elastomer of the composition of the invention may comprise at leastone nodular ethylene-alpha-olefin copolymer product of copolymer chainscomprising a nodule region of substantial cross-linking of copolymerchains second segments, with substantially uncrossed-linked copolymerchain first segments extending therefrom. Preferably, the chain firstsegments of the nodular copolymer are in the form of one contiguoussegment or a plurality of discontinuous segments, and comprise acopolymer chain of ethylene and an alpha-olefin, while the chain secondsegments comprise a copolymer of ethylene, alpha-olefin, and a couplingagent. Most preferably, these second segments constitute less than 50%by weight of each copolymer chain formed by the first and secondsegments, and are in the form of one contiguous segment or a pluralityof discontinuous segments.

In this embodiment, the coupling agent may be a Ziegler copolymerizablediene, preferably selected from the group consisting of norbornadiene,vinyl norbornene, and butenyl norbornene. Alternatively, the couplingagent may be a cross-linkable diene, preferably selected from a groupconsisting of ENB, 1,4-hexadiene, and dicyclopentadiene.

The elastomer of the composition of the invention may comprise acopolymer of ethylene and at least one other alpha-olefin monomer, whichcopolymer is a superposition of two or more copolymers modes each havinga MWD characterized by at least one of M_(w) /M_(n) less than 2 and aM_(z) /M_(w) less than 1.8. Preferably, the at least one otheralpha-olefin monomer contains 3-18 carbon atoms.

This copolymer may consist essentially ethylene, propylene, and straightchain acyclic diene selected from the group consisting of 1,4-hexadieneand 1,6-octadiene. Alternatively, this copolymer may consist essentiallyof ethylene, propylene, and 5-ethylidene-2-norbornene.

The composition of the invention may comprise:

(a) an ethylene-alpha olefin copolymer;

(b) one or more plastic compositions; and

(c) at least one copolymer, in an amount equal to approximately 80 wt. %or less of the composition, comprising a plurality of Ziegler-Nattacatalyzed polymer chains, substantially each of said chains being endcapped with at least one functional group-containing unit which isotherwise essentially absent from said copolymer chains, said functionalgroup being incorporated in a polymer selected from the group consistingof: ##STR1## the monomers thereof, and the mixtures thereof;

wherein R₁ through R₄ are hydrocarbons with 1-30 carbon atoms selectedfrom the group consisting of saturated or unsaturated, branched orunbranched, aliphatic, aromatic, cyclic, or polycyclic hydrocarbons,wherein R₅ is the same as R₄ but may additionally be hydrogen; andwherein x=1-10,000.

In the alternative, the at least one copolymer present in an amountequal to 80 wt. % or less of the composition may comprise a plurality ofcopolymer chains, substantially each of said chains being aZiegler-natta catalyzed polymer chain end capped with at least onefunctional group-containing unit which is otherwise essentially absentfrom said polymer chain.

The indicated functional group may be selected from the group consisting--CO₂ H, --OH, --SH, --X, --C--C-benzene, --C--C-(pyridine), --SO₂ H,SO₃ H, and mixtures thereof, wherein X is a halide selected from thegroup consisting of fluorine, chlorine, bromine, and iodine.

Alternatively this functional group may be selected from the groupconsisting of isocyanates, urethanes, nitriles, aromatic ethers andaromatic carbonates.

The indicated functional group containing unit may be selected from thegroup of polymers consisting of copolymers of ethylene and vinylacetate; ethylene and acrylic acid esters; vinyl acetate and fumaricacid esters; styrene and maleic acid esters; olefins and maleic acidesters; homopolyacrylates; and epoxidized natural rubber.

The composition of the invention may further comprise:

(a) at least one copolymer which comprises a plurality of copolymerchains, substantially each comprising:

I. a first segment, being in the form of one contiguous segment or aplurality of discontinuous segments, comprising a copolymer of ethyleneand an alpha-olefin; and

II. a second segment comprising a copolymer of ethylene, analpha-olefin, and at least one halogen-containing monomer selected fromthe group consisting of:

A. an olefinic chlorosilane of the formula

    SiRR.sub.x 'Cl.sub.3-x

wherein:

(i) x is in the range 0-2;

(ii) R is a Ziegler copolymerizable olefin;

and

(iii) R' is a hydrocarbon with 1-30 carbon atoms selected from the groupconsisting of saturated or unsaturated as well as branched or unbranchedaliphatic, aromatic, cyclic, and polycyclic hydrocarbons;

B. an olefinic hydrocarbon halide of the formula

    RR'X

wherein:

(i) R is a Ziegler copolymerizable olefin;

and

(ii) R' is a hydrocarbon with 1-30 carbon atoms selected from the groupconsisting of saturated or unsaturated as well as branched or unbranchedaliphatic, aromatic, cyclic, and polycyclic hydrocarbons; and

(iii) X is a halogen;

said second segment constituting less than 50 percent by weight of saidcopolymer chain, said second segment being in the form of one contiguoussegment or a plurality of discontinuous segments;

said at least one halogen-containing monomer being cross-linkable underconditions which do not cross-link said first segment to any substantialextent; and

(b) at least one plastic composition.

Alternatively, the elastomer of the composition of the invention maycomprise:

(a) at least one copolymer consisting essentially of a plurality ofcopolymer chains having at least one of M_(w) /M_(n) less than 2 andM_(z) /M_(w) less than 1.8, said copolymer comprising ethylene, analpha-olefin, and at least one halogen-containing monomer selected fromthe group consisting of:

I. an olefinic chlorosilane of the formula:

    SiRR.sub.x 'Cl.sub.3-x

wherein;

(i) x is in the range of 0-2;

(ii) R is a Ziegler copolymerizable olefin;

and

(iii) R' is a hydrocarbon with 1-30 carbon atoms selected from the groupconsisting of saturated or unsaturated as well as branched or unbranchedaliphatic, aromatic, cyclic, and polycyclic hydrocarbon; and

II. an olefinic hydrocarbon halide of the formula:

    RR'X

wherein:

(i) R is a Ziegler copolymerizable diene;

and

(ii) R' is a hydrocarbon with 1-30 carbon atoms selected from the groupconsisting of saturated or unsaturated as well as branched or unbranchedaliphatic, aromatic, cyclic, and polycyclic hydrocarbons; and

(iii) X is a halogen.

This copolymer may further comprise a non-conjugated diene selected fromthe group consisting of 5-ethylidene-2-norbornene, 1,4-hexadiene,dicylopentadiene, and mixtures thereof.

Further, in the alternative, the elastomer of the invention may compriseat least one nodular copolymer product of copolymer chains comprising:

A. a nodule region of substantial cross-linking of copolymer chainsecond segments substantially cross-linked by at least one cross-linkingagent, substantially each of said second segments comprising a copolymerof ethylene, an alpha-olefin, and at least one halogen-containingmonomer selected from the group consisting of:

(a) an olefinic chlorosilane of the formula

    SiRR.sub.x 'Cl.sub.3-x

wherein:

(i) x is in the range 0-2;

(ii) R is a Ziegler copolymerizable olefin; and

(iii) R' is a hydrocarbon with 1-30 carbon atoms selected from the groupconsisting of saturated or unsaturated as well as branched or unbranchedaliphatic, aromatic, cyclic, and polycyclic hydrocarbons; and

(b) an olefinic hydrocarbon halide of the formula RR'X wherein:

(i) R is a Ziegler copolymerizable olefin;

(ii) R' is a hydrocarbon with 1-30 carbon atoms selected from the groupconsisting of saturated or unsaturated as well as branched or unbranchedaliphatic, aromatic, cyclic, and polycyclic hydrocarbons;

(iii) X is a halogen; and

B. substantially uncross-linked copolymer chain first segments extendingtherefrom, substantially each of said first segments comprising acopolymer of ethylene and an alpha-olefin;

said halogen-containing monomer being cross-linkable under conditionswhich do not cross-link said first segments to any substantial extent.

Where the indicated halogen-containing monomer is an olefinicchlorosilane, it may be selected from the group consisting of vinyldimethylchlorosilane, vinyl ethyl dichlorosilane,1-hexenyl-6-dimethylchlorosilane, 1-hexenyl-6-trichlorosilane,1-octenyl-8-trichlorosilane, phenyl allyldichlorosilane,5-trichlorosilyl-2-norbornene, and 5-methyldichlorosilyl-2-norbornene.

Where the indicated halogen-containing monomer is an olefinichydrocarbon halide, it may be selected from the group consisting of5-chloromethyl-2-norbornene and 2-parachloromethylphenyl-5-norbornene.

These copolymers may be linked to the plastic through the indicatedhalogen-containing monomer. Where the halogen-containing monomer is anolefinic chlorosilane, such a link will form where the plasticcomposition is a polycarbonate, a polyamide, a polyester, apolyphenylene oxide, or an acetal. Where the halogen-containing monomeris an olefinic hydrocarbon halide, the link will form where the plasticcomposition is a polyamide.

The composition of the invention may also be subjected to curing.

The invention is also directed to the process for preparing thepreviously indicated compositions.

In one embodiment of the process, where the elastomer comprises acopolymer having at least one of M_(w) /M_(n) less than 2 and M_(z)/M_(w) less than 1.8, this elastomer is formed from a reaction mixturecomprised of catalyst, ethylene, and at least one other alpha-olefinmonomer, comprising conducting the polymerization of said at least onecopolymer:

(a) in at least one mix-free reactor;

(b) with essentially one active catalyst species;

(c) using at least one reaction mixture which is essentiallytransfer-agent free;

(d) in such a manner and under conditions sufficient to initiatepropagation of essentially all of said copolymer chains simultaneously,wherein chains of said at least one copolymer are dispersed within thereaction mixture.

This resulting elastomer is then blended with one or more plastics toform the composition of the invention.

In preparing the composition of the invention wherein the elastomercomprises a polymodal MWD copolymer, this copolymer may be prepared byvarying the previously indicated reaction process by any one of severalways.

In one of these variations, reaction mixture is withdrawn from thereactor at at least two predetermined times after initiation of thepolymerization and the copolymer withdrawn at each of said times isblended to form the polymodal MWD copolymer. Another variation employsat least two catalyst, each of which initiates the growth of polymerchains that obtain a different average molecular weight than thatinitiated by the other catalyst.

In a third alternative, at least two different mix-free reactors areemployed to form the different modes which are then blended to producethe polymodal MWD copolymer.

In a fourth embodiment, the polymodal MWD copolymer is produced byadding a catalyst reactivator to the reaction mixture afterpolymerization has progressed for a finite period of time.

A fifth embodiment employs a catalyst system which generates multipleactive catalyst species, each initiating the growth of polymer chainsthat obtain a different average molecular weight than those produced byother catalyst species.

To prepare a composition of the invention wherein the elastomer is anodular compolymer, the previously indicated reaction process is variedby permitting the polymerization to continue to at least 50% completion,at which point a coupling agent is introduced into the reaction mixture.The reaction is thereafter permitted to continue, thereby incorporatingthe coupling agent into the polymer so as to form a nodular copolymerwherein the polymer chains are linked to the coupling agent. The productwhich results is blended with one or more plastics to produce thecomposition of the invention.

To prepare an elastomer for the composition of the blend comprisingethylene, one or more alpha-olefin monomers, and at least one halogencontaining monomer selected from the group consisting of

(a) olefinic chlorosilane of the formula

    SiRR.sub.x 'Cl.sub.3-x

wherein;

(i) x is in the range 0-2;

(ii) R is a Ziegler compolymerizable olefin; and

(iii) R' is a hydrocarbon with 1-30 carbon atoms selected from the groupconsisting of saturated or unsaturated as well as branched or unbranchedaliphatic aromatic cyclic, and polycyclic hydrocarbons; and

(b) olefinic hydrocarbon halide of the formula RR'X wherein;

(i) R is a Ziegler copolymerizable olefin; and

(ii) R' is a hydrocarbon with 1-30 carbon atoms selected from the groupconsisting of saturated or unsaturated as well as branched or unbranchedaliphatic, aromatic, cyclic, and polycyclic hydrocarbons, and

(iii) X is a halogen;

wherein ethylene, one or more alpha-olefin monomers, and at least one ofthe previously indicated halogen-containing monomers are introduced intothe previously described reaction process. The resulting copolymer isblended with one or more plastic compositions to produce the compositionof the present invention.

A narrow-broad ethylene alpha-olefin copolymer, i.e., an ethylenealpha-olefin copolymer composition comprising:

(i) a first copolymer having at least one of M_(w) /M_(n) less than 2and M_(z) /M_(w) less than 1.8; and

(ii) a second copolymer having both M_(w) /M_(n) greater than or equalto 2 and M_(z) /M_(w) greater than or equal to 1.8; may be prepared forincorporation into the composition of the invention by forming the firstpolymer by the previously described process, reacting a second reactionmixture to produce the second copolymer, and then blending the first andsecond copolymers to form the elastomer for use with the composition ofthe invention. Subsequently, this elastomer is blended with one or moreplastic compositions to form the composition of the invention.

Any of these indicated processes may further be subjected to a curingstep for curing the composition.

The blends of the invention can have utility in high impactapplications. They can be employed in films, laminates, fabric coatings,tapes, and molded and extruded products, including sheet extrusionproducts.

The preferred elastomers for use in the blends of the invention are thesingle mode narrow MWD EPM and EPDM copolymers. The preferred plasticcompositions are polypropylene, polyethylene, particularly high densitypolyethylene, polystyrene, ethylene/vinyl acetate copolymer,ethylene/methyl methacrylate copolymer, and heteroblockpropylene-ethylene copolymers. The use of polypropylene and polyethylenetogether is also preferred.

Where the plastic composition of the invention is polypropylene, theblends preferably comprise approximately 2-50 weight percent elastomerand approximately 98-50 weight percent polypropylene.

Blends employing heteroblock propylene-ethylene copolymer preferablycomprise approximately 2-50 weight percent of elastomer andapproximately 98-50 weight percent of the heteroblock copolymer. Theheteroblock copolymer preferably comprises approximately 50-98 weightpercent, more preferably approximately 60-95 weight percent, of apolypropylene block, and preferably approximately 2-50 weight percent,more preferably approximately 5-40 weight percent of a post block ofethylene and propylene. The post block preferably comprisesapproximately 20-75 weight percent, more preferably 25-50 weight percentethylene.

DETAILED DESCRIPTION OF THE INVENTION

The preferred Cozewith et al. composition for use with the blends ofthis invention are the single mode narrow MWD copolymers, in particularthe EPM and EPDM copolymers, as disclosed in U.S. Pat. No. 4,540,753.

These narrow MWD copolymers in accordance with the present invention arepreferably made in a tubular or batch reactor operating under carefullycontrolled conditions.

As indicated in Cozewith et al. at column 7, lines 4-36, when a tubularreactor is employed with monomer feed only at the tube inlet, ethylenewill be preferentially polymerized. The result is copolymer chains withprogressively lower ethylene and higher propylene concentration, asschematically presented below: ##STR2## This resulting chain isintramolecularly heterogenous.

As indicated at column 7, lines 37-48, where more than two monomers areused in the production of the narrow and broader MWD copolymers, as inthe production of EPDM, all properties related to homogeneity andheterogeneity will refer to the relative ratio of ethylene to the othermonomers in the chain. Further, as earlier indicated, the propertyrelated to intramolecular compositional dispersity shall be referred toas Intra-CD, and the property related to intermolecular compositionaldispersity shall be referred to as Inter-CD.

The preferred copolymers for the narrow MWD copolymers are comprised ofethylene and at least one other alpha-olefin. It is believed that suchalpha-olefins may include those containing 3 to 18 carbon atoms, e.g.,propylene, butene-1, pentene-1, etc. Alpha-olefins of 3 to 6 carbons arepreferred due to economic considerations. The most preferred copolymersfor the narrow MWD copolymers are those comprised of ethylene andpropylene, or of ethylene, propylene and diene.

As is well known to those skilled in the art, copolymers of ethylene andhigher alpha-olefins such as propylene often include other polymerizablemonomers. Typical of these other monomers may be non-conjugated dienessuch as the following non-limiting examples:

a straight chain acyclic dienes such as: 1,4-hexadiene; 1,6-octadiene;

b. branched chain acyclic dienes such as: 5-methyl-1,4-hexadiene;3,7-dimethyl-1,6-octadiene; 3,7-dimethyl-1,7-octadiene and the mixedisomers of dihydromyrcene and dihydroocimene;

c. single ring alicyclic dienes such as: 1,4-cyclohexadiene;1,5-cyclooctadiene; and 1,5-cyclododecadiene;

d. multi-ring alicyclic fused and bridged ring dienes such as:tetrahydroindene; methyltetrahydroindene; dicyclopentadiene;bicyclo-(2,2,1)-hepta-2,5-diene; alkenyl, alkylidene, cycloalkenyl andcycloalkylidene norbornenes such as 5-methylene-2-norbornene (NMB),5-ethylidene-2-norbornene (ENB), 5-(4-cyclopentenyl)-2-norbornene;5-cyclohexylidene-2-norbornene.

Of the non-conjugated dienes typically used to prepare these copolymers,dienes containing at least one of the double bonds in a strained ringare preferred. The most preferred diene is 5-ethylidene-2-norbornene(ENB). The amount of diene (wt. basis) in the copolymer could be fromabout 0% to 20%, with 0% to 15% being preferred. The most preferredrange is 0% to 10%.

As already noted, the most preferred copolymer for the narrow MWDcopolymer is ethylene-propylene or ethylene-propylene-diene. In eitherevent, the average ethylene content of the copolymer could be as low asabout 10% on a weight basis. The preferred minimum is about 25%. A morepreferred minimum is about 30%. The maximum ethylene content could beabout 90% on a weight basis. The preferred maximum is about 85%, withthe most preferred being about 80%.

The molecular weight of the narrow MWD copolymer can vary over a widerange. It is believed that the weight average molecular weight could beas low as about 2,000. The preferred minimum is about 10,000. The mostpreferred minimum is about 20,000. It is believed that the maximumweight average molecular weight could be as high as about 12,000,000.The preferred maximum is about 1,000,000. The most preferred maximum isabout 750,000.

The molecular weight distribution (MWD) of the narrow MWD copolymer isvery narrow, as characterized by at least one of a ratio of M_(w) /M_(n)of less than 2 and a ratio of M_(z) /M_(w) of less than 1.8. As relatesto EPM and EPDM, some typical advantages of such copolymers havingnarrow MWD are greater resistance to shear degradation, and whencompounded and vulcanized, faster cure and better physical propertiesthan broader MWD materials.

The narrow MWD copolymer is produced by polymerization of a reactionmixture comprised of catalyst, ethylene and at least one additionalalpha-olefin monomer. Solution polymerizations are preferred.

Any known solvent for the reaction mixture that is effective for thepurpose can be used in conducting such solution polymerizations. Forexample, suitable solvents are hydrocarbon solvents such as aliphatic,cycloaliphatic and aromatic hydrocarbon solvents, or halogenatedversions of such solvents. The preferred solvents are C₁₂ or lower,straight chain or branched chain, saturated hydrocarbons, C₅ to C₉saturated alicyclic or aromatic hydrocarbons or C₂ to C₆ halogenatedhydrocarbons. Most preferred are C₁₂ or lower, straight chain orbranched chain hydrocarbons, particularly hexane. Nonlimitingillustrative examples of solvents are butane, pentane, hexane, heptane,cyclopentane, cyclohexane, cycloheptane, methyl cyclopentane, emthylcyclohexane, isooctane, benzene, toluene, xylene, chloroform,chlorobenzenes, tetrachloroethylene, di-chloroethane andtrichloroethane.

The composition of the narrow MWD copolymers can vary between chains aswell as along the length of the chain. It is preferable to minimize theamount of interchain variation, which, as indicated, is measured byInter-CD. Inter-CD is characterized by the fraction and totalcomposition differences as more fully explained at column 7, lines 49-64of Cozewith et al., and is measured by techniques using solventcompositions, as also more fully described in this portion of thepatent.

It is preferred that the Inter-CD of the copolymer is such that 95 wt. %of the copolymer chains have an ethylene composition that differs fromthe copolymer average weight percent ethylene composition by 15 wt. % orless. The preferred Inter-CD is about 13% or less, with the mostpreferred being about 10% or less.

It is also preferred that the Intra-CD of the narrow MWD copolymer besuch that at least two portions of an individual intramolecularlyheterogeneous chain, each portion comprising at least 5 weight percentof the chain, differ in composition from one another by at least 5weight percent ethylene. The Intra-CD can be such that at least twoportions of copolymer chain differ by at least 10 weight percentethylene. Differences of at least 20 weight percent, as well as of atleast 40 weight percent ethylene, are also considered to be inaccordance with the present invention. Having a polymer chain which isrich in propylene at one end and rich in ethylene at the other end isadvantageous for morphology and property control in blends ofpolyethylene and polypropylene plastics with EDM and EPDM copolymers.

Intra-CD for the narrow MWD copolymer is established by an experimentalprocedure wherein Inter-CD is first established as previously discussed,and the polymer chain is then broken into fragments alongs its contour,whereupon the Inter-CD of the fragments is determined. The difference inthe two results is due to Intra-CD, as more fully represented at theillustrative example at column 8, line 33 through column 9, line 31 ofCOZEWITH et al.

In order to determine the fraction of a polymer which isintramolecularly heterogenous in a mixture of polymers combined fromseveral sources, the mixture must be separated into fractions which showno further heterogeneity upon subsequent fractionation. These fractionsare subsequently fractured and fractionated to reveal which areheterogeneous.

The properties of the required fragments, and the necessaryfractionation technique, are described in detail at column 9, line 39through column 10, line 38 of COZEWITH et al.

Ethylene content for the narrow MWD copolymer can be measured by ASTMtests, and proton and carbon 13 nuclear magnetic resonance, as morefully described at column 10, lines 39-54 of COZEWITH et al.

Molecular weight and molecular weight distributions can be measured bychromatography techniques, and numerical analyses are performed bycomputer, as more fully described at column 10, line 55 through column11, line 8 of COZEWITH et al.

The polymerization process for producing a single mode narrow MWDcopolymer should be conducted such that:

a. the catalyst system produces essentiallly one active catalystspecies;

b. the reaction mixture is essentially free of chain transfer agents;and

c. the polymer chains are essentially all initiated simultaneously,which is at the same time for a batch reactor, or at the same pointalong the length of the tube for a tubular reactor.

The narrow MWD copolymer may be produced in a mix-free reactor system,which is one in which substantially no mixing occurs between portions ofthe reaction mixture that contain polymer chains initiated at differenttimes. A suitable process, as disclosed in COZEWITH et al., employs atubular reactor with a catalyst system that gives essentially one activecatalyst species, selecting polymerization conditions such that all thepolymer chains are initiated at the reactor inlet, and chain transfer issubstantially absent along the tube length.

As disclosed in COZEWITH et al., a single continuous flow stirred tankreactor (CFSTR) will mix polymer chains initiated at different times,and is therefore not suitable for producing the narrow MWD copolymer.However, it is well known that 3 or more stirred tanks in series withall of the catalyst fed to the first reactor can approximate theeperformance of a tubular reactor. Accordingly, such tanks in series areconsidered to be in accordance with the present invention, and fallwithin the term "tubular" as used herein.

Another suitable reactor is a batch reactor, preferably equipped withadequate agitation, to which the catalyst, solvent, and monomer areadded at the start of the polymerization. The charge of reactants isthen left to polymerize for a time long enough to produce the desiredproduct. For economic reasons, a tubular reactor is preferred to a batchreactor for performing the processes of this invention.

The temperature of the narrow MWD reaction mixture should also be keptwithin certain limits. The temperature at the ractor inlet should behigh enough to provide complete, rapid chain initiation at the start ofthe polymerization reaction. The length of time the reaction mixturespends at high temperature must be short enough to minimize the amountof undesirable chain transfer and catalyst deactivation reactions.

Temperature control of the narrow MWD reaction mixture, as describedmore fully in COZEWITH et al., is maintained by using prechilled feedand operating the reactor adiabatically. As an alternative to feedprechill, a heat exchanger, as more fully described in COZEWITH et al.,may be employed. Well known autorefrigeration techniques may be used inthe case of batch reactors or multiple stirred reactors in series.

If adiabatic reactor operation is used, the inlet temperature of thereactor feed could be about from -50° C. to 150° C. It is believed thatthe outlet temperature of the reaction mixture could be as high as about200° C. The preferred maximum outlet temperature is about 70° C. Themost preferred maximum is about 50° C.

Certain reaction parameters for the process of producing the narrow MWDcopolymer, such as preferred maximum copolymer concentration at thereactor outlet, flow rate of the reaction mixture, and residence time ofthe reaction mixture in the mix-free reactor for the process of makingthe narrow MWD copolymer, are more fully described at column 17, line 57through column 18, line 23 of COZEWITH et al.

Briefly as to these parameters, the most preferred maximum polymerconcentration at the reactor outlet is 15 wt/100 wt diluent, with apreferred minimum of 2 wt/100 wt diluent, and a most preferred minimumof at least 3 wt/100 wt diluent. As to residence time, a preferredminimum is about 10 seconds, and a most preferred minimum is about 15seconds; the maximum could be as high as about 3,600 seconds, with apreferred maximum of about 1,800 seconds, and a most preferred maximumof about 900 seconds. The flow rate should be high enough to providegood mixing of the reactants in the radial direction and minimize mixingin the axial direction.

Additional solvents and reactants may be added along the length of atubular reactor, or during the course of polymerization in a batchreactor.

In the process for making the narrow MWD copolymer, it is essential thatthe polymer chains are all initiated simultaneously.

In addition to the disclosed reactor systems, others having the benefitof the present disclosure may be employed. Further, more than onereactor could be used in parallel, or in series with a multiple monomerfeed.

Accordingly, processes for producing a single mode narrow MWD copolymerin accordance with the present invention are carried out:

(a) in at least one mix-free reactor,

(b) using a catalyst system that produces essentially one activecatalyst species,

(c) using at least one reaction mixture which is essentially transferagent-free, and

(d) in such a manner and under conditions sufficient to initiatepropagation of essentially all polymer chains simultaneously.

Any of the process means disclosed in the COZEWITH et al. patent, usingthe reaction components, parameters, additives, and apparatus alsodisclosed therein, may be employed to produce the narrow MWD copolymer.The M_(w) /M_(n) value of this copolymer will be less than 2.0, and aslow as 1.2-1.5.

As more fully described at column 13, line 64 through column 14, line25, of COZEWITH et al., the catalyst used in the process for producingthe narrow MWD copolymer should preferably be such as to yieldessentially one active catalyst species in the reaction mixture. As alsomore fully discussed at this portion of COZEWITH et al., additionalactive catalyst species can be present which produce as much as 35% byweight of the total copolymer, but preferably less than 10% or less byweight of the copolymer, if only the narrow MWD polymer is to be formed.Accordingly, where only the narrow MWD polymer is to be formed, the oneactive species should provide for at least 65%, or preferably at least90%, of the total copolymer produced.

Techniques for measuring the activity of and for characterizing catalystspecies are discussed at column 14, lines 14-25 of COZEWITH et al.

The catalyst systems employed in producing the narrow MWD copolymer maybe those disclosed in COZEWITH et al., prepared as disclosed in thispatent.

Catalyst system to be used in carrying out processes for producing thenarrow MWD copolymer may be Ziegler catalysts, which may typicallyinclude:

(a) a compound of a transition metal, i.e., a metal of Groups I-B,III-B, IV-B, VI-B, VII-B, and VIII of the Periodic Table, and

(b) an organometal compound of a metal of Groups I-A, II-A, II-B andIII-A of the Periodic Table.

The preferred catalyst system in practicing processes in accordance withthe present invention comprises a hydrocarbon soluble vanadium compound,in which the vanadium valence is 3 to 5, an organo-aluminum compound,with the proviso that the catalyst system yields essentially one activecatalyst species as described above. At least one of the vanadiumcompound/organo-aluminum pair selected must also contain avalence-bonded halogen.

In terms of formulas, vanadium compounds useful in practicing processesin accordance with the present invention could be: ##STR3## where

X=O-3 and R=a hydrocarbon radical;

VCl₄ ;

VO(AcAc)₂,

where AcAc=acetyl acetonate;

V(AcAc)₃ ;

VOCl_(x) (AcAc)_(3-x), (2)

where x=1 or 2; (2)

VCl₃.nB, and mixtures thereof

where n=2-3 and B=Lewis base capable of making hydrocarbon-solublecomplexes with VCl₃, such as tetrahydrofuran,2-methyl-tetrahydrofuranand dimethyl pyridine.

In formula (1) above, R preferably represents a C₁ to C₁₀ aliphatic,alicyclic or aromatic hydrocarbon radical such as ethyl (Et), phenyl,isopropyl, butyl, propyl, n-butyl, i-butyl, hexyl, cyclohexyl, octyl,naphtyl, etc. Non-limiting, illustrative examples of formula (1)compounds are vanadyl trihalides, alkoxy halides and alkoxides such asVOCl₃ VOCl₂ (OBu) where Bu=butyl, and VO(OC₂ H₅)₃. The most preferredvanadium compounds are VCl₄, VOCl₃, and VOC₂ (OR).

As already noted, the co-catalyst is preferably an organo-aluminumcompound. In terms of chemical formulas, these compounds could be asfollows:

    ______________________________________                                        AlR.sub.3,        Al(OR')R.sub.2                                              AlR.sub.2 Cl,     R.sub.2 Al--O--AlR.sub.2                                    AlR'RCl           AlR.sub.2 I                                                 Al.sub.2 R.sub.3 Cl.sub.3,                                                    AlRCl.sub.2,      and mixtures thereof                                        ______________________________________                                    

where R and R' represent hydrocarbon radicals, the same or different, asdescribed above with respect to the vanadium compound formula.

A preferred organo-aluminum compound is Al₂ R₃ Cl₃.

The most preferred organo-aluminum co-catalyst is ethyl aluminumsesquichloride (EASC)-Al₂ Et₃ Cl₃.

Where the catalyst system used in producing the narrow MWD copolymercomprises VCl₄ and Al₂ R₃ Cl₃, preferably where R is ethyl, the moleratio of aluminum/vanadium, as more fully described as column 15, lines37-54 of COZEWITH et al., should be at least 2, with a preferred minimumof about 4, and a maximum of about 25, a preferred maximum of about 17,and a most preferred maximum of about 15.

The catalyst system can be selected, and the reactor temperature set, sothat negligible chain transfer with aluminum alkyl or propylene occursalong the reactor length. Essentially all chain growth must start nearthe catalyst feed point. These requirements can be met with catalystsystems containing EASC.

The catalyst components are preferably premixed, as is described inCOZEWITH et al. in more detail, and aged prior to introduction in to thereactor. The preferred minimum aging period is about 0.1 second. Morepreferably, this period is about 0.5 seconds; most preferably, about 1second. The maximum aging period is about 200 seconds, or, morepreferably, about 100 seconds. Most preferably, this period is about 50seconds.

The premixing can be performed at temperatures of 40° C. or below. Morepreferably, premixing is performed at 25° C. or below; most preferably,at 15° C. or below.

The elastomer composition comprising a narrow MWD copolymer and a broadMWD copolymer, is also suitable for use in the blends of the invention.

The narrow MWD component of this composition is the narrow MWD copolymerpreviously described, prepared by the indicated processes.

No restrictions apply to processes for producing the broader MWDcopolymer which are well known. This process can be practiced with avariety of catalyst systems and polymerization conditions, provided thatthe desired quantity and molecular weight of polymer is obtained. Thesame monomers, solvents, and catalysts as disclosed for producing thenarrow MWD copolymer may be used to produce the broader MWD copolymer.Reaction parameters may be varied to produce the broader MWD of thiscopolymer. Such reaction parameters which may be varied are temperatureat the inlet and/or outlet of the reactor, as well as through the bodyof the reactor.

Chain transfer agents such as hydrogen or diethyl zinc, as disclosed inCOZEWITH et al., may be added to the process to broaden MWD.

MWD may further be broadened by catalyst deactivation, as disclosed inCOZEWITH et al.

MWD may further be broadened by adding diethyl aluminum chloride (DEAC)to the reaction.

The broader MWD copolymer may be prepared in a tubular reactor or in astirred tank. The stirred tank may be a continuous flow stirred tankreactor (CFSTR).

According to one novel process for producing the narrow-broad MWDcomposition, a first reactor or reactors operating at conditions chosento produce the narrow MWD copolymer can be operated in series or inparallel with a second reactor operating to produce the broader MWDcopolymer. The second tubular reactor can be separate from the firstreactor, or it can be an extension thereof, as long as the correctpolymerization conditions are imposed.

When the second reactor is a continuous flow stirred reactor, typicaloperating conditions are a temperature of 20°-70° C. and a residencetime of 5-60 minutes. The exit polymer concentration from this reactoris preferably in the range of 2 wt/100 wt diluent to 20 wt/100 wtdiluent. Any of the catalyst systems previously disclosed can be used inthe second reactor to form the second polymer. It is well known in theart that the choice of catalyst components used in a continuous flowstirred reactor influences the MWD of the polymer produced. By properselection of the catalyst, a second polymer with M_(w) /M_(n) between 2and 100 can be obtained.

The narrow-broad MWD composition can be formed by first preparing thenarrow MWD copolymer in a mix free tubular reactor. This processutilizes conditions sufficient to simultaneously initiate propagation ofall copolymer chains of the narrow MWD copolymer, and the reactionmixture employed comprises a catalyst for generating essentially onecatalyst species having a life longer than the residence time in thereactor. Then, this narrow MWD copolymer is reacted in a stirred tankreactor with additional monomer to form the broader MWD copolymer.

The composition can also be produced by preparing the broader MWDcopolymer in a second tubular reactor operated in parallel with thetubular reactor used to prepare the narrow MWD copolymer, and thenblending the products.

The composition can be prepared in the tubular reactor used to preparethe narrow MWD copolymer. The broader MWD copolymer of the blend can beformed by injecting a catalyst, or a transfer agent, or additionalreaction mixture, at at least one location along the tubular reactor.

Where the narrow MWD copolymer comprises ethylene-propylene-couplingagent containing chains, the broader MWD copolymer components can beprepared by cross-linking the coupling agents to nodularize a portion ofthe chains, and the nodular chains are then blended with the narrow MWDchains.

Another means comprises first preparing the broader MWD copolymer in atubular reactor by means of a catalyst suitable for preparing thiscopolymer, and then injecting a catalyst suitable for preparing thenarrow MWD copolymer, and, alternatively, also injecting additionalmonomer, to initiate the reaction for forming the narrow MWD copolymer.

In the case where broad and narrow components are generated"simultaneously", the reactor is mix-free only for the narrow MWDcatalyst component. Initiation of the broad MWD component would extendover a period of time which is comparable to chain lifetime, and mayoverlap at some point with initiation of the narrow MWD copolymer.Substantially no mixing occurs between portions of the reaction mixturethat contain polymer chains initiated by the narrow MWD catalyst atdifferent times.

In the mix-free tubular reactor employed to prepare the narrow MWDcopolymer, the broader MWD copolymer can be prepared by recycling aportion of the narrow MWD copolymer from the reactor outlet to a pointalong the reactor.

Another means for preparing the narrow-broad composition in a singlemix-free tubular reactor is by adding, during the process for preparingthe narrow copolymer, catalyst reactivator, and, optionally, additionalmonomers, downstream of the reactor inlet to form the broader MWDcopolymer component.

The narrow MWD copolymer can be prepared in a mix-free batch reactor,utilizing conditions sufficient to simultaneously initiate propagationof all copolymer chains of the narrow MWD copolymer. The reactionmixture employed comprises a catalyst for preparing essentially onecatalyst species, and is essentially free of transfer agents.

The narrow-broad MWD composition can also be formed by employing a batchreactor, and then adding the resulting narrow MWD copolymer to the broadMWD copolymer. It can also be formed by preparing the broader MWDcopolymer in a batch reactor, and thereafter blending it with the firstcopolymer made in the batch reactor.

The narrow and broad MWD copolymers can be simultaneously formed in asingle batch reactor by introducing into the reaction mixture bothcatalyst for generating essentially one catalyst species, to produce thenarrow MWD copolymer, and by also introducing a catalyst suitable forforming the second copolymer.

The copolymers disclosed in the previously indicated Application No.U.S. Pat. No. 4,789,714, comprising a superposition of two or morenarrow MWD copolymers, and hereinafter referred to, for convenience, aspolymodal copolymers, are also suitable for use with the blends of thisinvention.

As previously indicated, single mode MWD copolymers are produced bycarrying out a polymerization reaction:

(a) in at least one mix free reactor,

(b) using catalyst systems such that each component or mode in a MWD isproduced by essentially one active catalyst species,

(c) using at least one reaction mixture which is essentially transferagent-free, and

(d) in such a manner and under conditions sufficient to initiatepropagation of essentially all polymer chains made with a particularcatalyst species simultaneously.

To produce the polymodal MWD copolymer, these polymerization conditionsare used to generate each of the narrow MWD modes that comprise thefinal polymer product. A number of techniques are available forachieving this:

(1) In a single mix free reactor operated as described above, portionsof the polymer product can be withdrawn after varying times in a batchreactor or at varying distances along a tubular reactor representingdifferent average molecular weights and these portions can be blended.

(2) Mix-free reactors can be operated either in parallel or sequentiallyand the products blended.

(3) Two or more catalysts that form narrow MWD polymer of differingmolecular weight can be added at the onset of polymerization in amix-free reactor. Each catalyst must meet the requirements of minimizingchain transfer and initiating simultaneous propagation of all the chainsproduced by that catalyst.

(4) A catalyst system that generates multiple active catalyst speciescan be added at the start of the polymerization. Each catalyst speciesproduced must give simultaneous chain initiation and minimize chaintransfer.

(5) Additional catalyst and monomer, if desired, can be added at varyinglengths along a tubular reactor, or times in a batch reactor, toinitiate the formation of additional MWD modes. The catalysts can be thesame or different, as long as chains are initiated simultaneously andchain transfer is minimized.

(6) For catalyst systems that show a decay in activity as a function oftime due to deactivation, catalyst reactivator can be added during thecourse of the polymerization to regenerate the dead catalyst and form anew mode of narrow MWD copolymer.

Catalyst reactivators are well known in the art for increasing theproductivity of vanadium Ziegler catalysts. These materials rejuvenatecatalyst sites that have become inert due to termination reactions, andthereby cause reinitiation of polymer chain growth. When added to areactor operating according to the process of this invention, catalystreactivators have an effect similar to that of adding a second catalystfeed. Many reactivators are known, and examples of suitable materialscan be found in U.S. Pat. Nos. 3,622,548, 3,629,212, 3,723,348,4,168,358, 4,181,790 and 4,361,686. Esters of chlorinated organic acidsare preferred reactivators for use with the vanadium catalyst systems ofthis invention. Especially preferred is butyl perchlorocrotanate.

In the processes that utilize multiple catalysts or multiple catalystsadditions during the course of polymerization, the mix free condition ofthe reactor refers to the polymer chains of each individual mode of theMWD and not to the polymer as a whole.

A preferred multiple catalyst system comprises VCl₄ combined with VOCl₃and an alkyl aluminum sesquihalide as a cocatalyst. The resultantpolymer is a bimodal MWD polymer.

The end-capped, star, graft, and block copolymers disclosed in thepreviously indicated Application Ser. No. 813,848 are also suitable foruse with the blends of this invention.

In the process disclosed therein, ethylene propylene polymerizations arecapped by a capping agent having at least one functional group whichpermits it to attach to the polymer end chain. Most preferably, thecopolymers upon which the end capping function is performed are EPMcopolymers and EPDM terpolymers, as previously disclosed. Further, priorto end capping the copolymer is preferably a narrow MWD copolymer.

The polymerization process is most preferably performed:

(a) in at least one mix-free reactor,

(b) using a catalyst system that produces essentially one activecatalyst species,

(c) using at least one reaction mixture which is essentially transferagent-free, and

(d) in such a manner and under conditions sufficient to initiatepropagation of essentially all polymer chains simultaneously.

After growing the polymer chains to the desired molecular weight, endcapping agent is fed to add one or more end capping units to the polymerchain, or to produce a structure grafted by the ethylene alpha-olefinchains.

It will be understood that, depending upon the desired functionality ofthe chains, end capping units which have one or a multiplicity offunctionalities, and which themselves may or may not polymerize, areintroduced into the reactor.

As noted above, the end cap units may have one or more than onefunctionality.

Unifunctional end capping units may be selected from the groupconsisting of: --CO₂ H (1), --OH (2), --SH (3), --X (4), --C--C--benzene(5), --C--C--(pyridine) (6), --SO₂ H (7), --SO₃ H (8), and mixturesthereof, wherein X is a halide selected from the group consisting offluorine, chlorine, bromine, and iodine.

The capping agents used to prepare the above capping units, as numbered,are: ##STR4## wherein R₆ through R₁₁ are selected from the groupconsisting of alkyl having 1-30 carbon atoms, saturated or unsaturated,branched or unbranched, aliphatic, aromatic, cyclic, or polycyclichydrocarbons;

    ______________________________________                                        sulfur and H.sub.2 C═S                                                                           (3)                                                    fluoride, chloride, bromide, iodine,                                                                 (4)                                                    and mixtures thereof                                                          styrene                (5)                                                    vinyl pyridine         (6)                                                    SO.sub.2               (7)                                                    SO.sub.3               (8)                                                    ______________________________________                                    

In the case of unsaturated ester and ketone capping agents, ketone andester functionality, in addition to hydroxyl functionality, may beproduced.

By way of example only, the following capping units may be used:acetaldehyde, methyl acetate, and methyl ethyl ketone.

The chains are then used as is, or may be nodularized as disclosed inthe previously indicated U.S. Pat. No. 4,882,406.

In yet another approach, the end cap may be composed of one monomer, ora polymer chain of the monomers to form a novel composition composed ofthe original alpha-olefin chain which is coupled to the monomer orpolymer chain, i.e., a graft copolymer. Where the functional group isincorporated as a polymer, the polymer itself may be formed prior to orafter being linked to the original polymer.

In this embodiment the functional group may be incorporated as a polymerunit selected from the group consisting of: ##STR5## the monomersthereof, and mixtures thereof; wherein R₁ through R₄ are selected fromthe group consisting of: alkyl having 1-30 carbon atoms, saturated orunsaturated, branched or unbranched, aliphatic, aromatic, cyclic, orpolycyclic hydrocarbons, and R₅ is the same as R₄ but may additionallybe hydrogen, and wherein x=1-10,000.

Specific compounds include: polycylacrylate, polymethylvinylketone, andpolystyrene.

The process of the invention used to end cap with the above monomers orpolymers comprises reacting the growing chain, respectively, with thefollowing capping agents: ##STR6##

Specific compounds include: decylacrylate, methylvinyl ketone, styrene,vinyl pyridine, vinyl acetate, methyl vinyl ether, and methylmethacrylate.

End capping with any of the above agents (1)-(7) may be performed byinjecting the capping agent into the polymerization reactor to quenchfurther ethylene alpha-olefin Ziegler-Natta polymerization, after whichthe end capping reagent itself may be polymerized to form a blockcopolymer. For further polymerization to occur in this fashion thecatalyst used in the original polymerization must be capable ofpolymerizing the agent by some mechanism, either anionic, radical,cationic, or coordination.

This additional polymerization of the agent may be formed in the samereactor, or in a different reactor.

As previously stated, end capped copolymers are suitable for blendingwith plastics compositions. Moreover, they may be employed ascompatiblizers in blends of EPM and EPDM copolymers with plasticcompositions, especially engineering resins, such as nylons,polycarbonates, polyesters, acetals, and polyphenylene oxides. When usedfor such purposes, they are preferably present in such blends at up toapproximately 80 percent by weight of the blend.

The end capping group may be polymeric, in which case star shaped orgraft polymers may be formed. These polyfunctional end capping groupsmay be selected from the group of copolymers consisting of: copolymersof ethylene and vinylacetate (1); ethylene and acrylic acid esters..(2); vinyl acetate and fumaric acid esters (3); styrene and maleic acidesters (4); olefins and maleic acid esters (5); homopolyacrylates (6);and epoxidized natural rubber (7).

The nodular copolymers disclosed in the previously indicated U.S. Pat.No. 4,882,406 are also suitable for use with the blends of thisinvention.

These nodular copolymers comprises ethylene, at least one alpha-olefinmonomer, and a non-conjugated diene copolymer. Prior to coupling, theindividual polymer chains of the nodular copolymer have at least onesegment that contains only ethylene and the alpha-olefin, and a secondsegment that contains ethylene, the alpha-olefin, and the non-conjugateddiene. Prior to the formation of the nodular branched copolymer thecopolymer is a narrow MWD copolymer, as defined herein.

The processes for preparing these nodular copolymers are most preferablycarried out:

(a) in at least one mix-free reactor,

(b) using a catalyst system that produces essentially one activecatalyst species,

(c) using at least one reaction mixture which is

essentially transfer agent-free, and

(d) in such a manner and under conditions sufficient to initiatepropagation of essentially all polymer chains simultaneously.

To form the nodular copolymers, the polymer chains formed in thepolymerization are coupled by reacting the residual double bonds, in thenon-conjugated diene in one polymer chain, with similar double bonds inother chains. Th coupling reaction can be catalyzed by either Ziegler,cationic, free radical catalysts, or olefin coupling agents.

The preferred reactor for preparing these copolymers is a tubularreactor. When polymerizing in a tube, the ethylene and propylene are fedto the reactor inlet along with a suitable Ziegler catalyst. Thecatalyst is preferably chosen so that it produces essentially one activecatalyst species. Also, chain transfer reactions during thepolymerization must be minimized. It is well known that ethylene is muchmore readily polymerized than propylene. Consequently, the concentrationof monomer changes along the tube in favor of propylene as the ethyleneis depleted The result is copolymer chains which are higher in ethylenecontent in the chain segments grown near the reactor feed inlet andhigher in propylene in the segments grown near the reactor outlet. Theresulting chain is intramolecularly heterogeneous. The extent ofheterogeneity in ethylene/propylene compositions can be moderatedsomewhat by feeding additional ethylene at points along the reactor tokeep the ethylene/propylene monomer ratio at a more constant value. Anobject is to produce chains with a minimum of interchain compositionalvariation in order to assure uniform coupling. This is accomplished byutilizing a Ziegler catalyst that forms essentially one active catalystspecies, minimizing chain transfer reactions initiating propagation ofessentially all chains simultaneously, and conducting the polymerizationsuch that the major portion of the catalyst remains active for theentire length of time that polymerization is occurring in the reactor.The tubular reactor is also operated at conditions such that thecopolymer chains have a narrow MWD characterized by at least one of theratios of M_(w) /M_(n) and M_(z) /M_(w) being less than 2.0 and 1.8,respectively, prior to coupling.

In one embodiment, polymerization of the ethylene and propylene isinitiated at the reactor inlet and continued until a first polymersegment forms comprising at least 50% of the weight of the total polymerto be produced Additional monomer feed is then added to the tubeconsisting of non-conjugated diene, either alone or in combination withthe other monomer and/or solvent. At the point of non-conjugated dieneaddition, at least 50% of the ultimate aniticipated mass of the polymershould have been formed. A second chain segment is then formed with anon-conjugated diene content of at least 0.1 mole 1% and with a M_(w)value of at least 2000. If the first polymer segment is formed as aseries of discontinuous segments, the first segment shall be consideredto include the segments as a whole for definitional purposes.

Several techniques are available for producing the nodular branchedpolymer of this invention. If the non-conjugated diene has both doublebonds polymerizable by the Ziegler catalyst, branching will occursimultaneously with polymerization in the reactor. In this case thepolymer exiting the reactor will be the final product.

If coupling is to be catalyzed cationically, the cationic catalyst caneither be added to the tubular reactor, to carry out the coupling in thereactor, or to the polymer product exiting the reactor so that thecoupling can be carried out in a separate process step. Free radicalcoupling catalysts are normally Ziegler catalyst poisons and will notperform at polymerization conditions. In this case, the coupling agentmust be added, and the coupling performed, subsequent to thepolymerization. Olefin cross-linking ageants may also be used in asimilar manner

As already noted, the first copolymer segment in accordance with thepresent invention is comprised of ethylene and at least one otheralpha-olefin. It is believed that such alpha-olefin could include thosecontaining 3 to 18 carbon atoms, e.g., propylene, butene-1, pentent-1,etc. Alpha-olefins of 3 to 6 carbons are preferred due to economicconsiderations. The most preferred alpha-olefin in accordance with thepresent invention is propylene.

The diene monomers suitable for use in the practice of this invention bywhich the narrow MWD polymers prepared by this invention are coupled,are of two types: (1) non-conjugated dienes capable of being Zieglercatalyst polymerized via both double bonds; and (2) the non-conjugateddienes of the type used to prepare EPDM where the non-conjugated dieneshas only one Ziegler catalyst polymerizable double bond, and the otherbond is cross-linkable by cationic or free radical catalysts, or byolefin cross-linking agents.

Typical of the coupling agents that can be used to produce the secondterpolymer segment of the chain are the following non-limiting examples

(a) straight chain acyclic dienes such as: 1,4-hexadiene; 1,6-octadiene;

(b) branched chain acyclic dienes such as: 5-methyl-1, 4-hexadiene;3,7-dimethyl-1, 6-octadiene; 3,7-dimethyl.-1, 7-octadiene and the mixedisomers of dihydromyrcene and dihydroocimene;

(c) single ring alicyclic dienes such as: 1,4-cyclohexadiene;1,5-cyclooctadiene; and 1,5-cyclododecadiene;

(d) multi-ring alicyclic fused and bridged ring dienes such as:teetrahydroindene; methyltetrahydroindene; dicyclopentadiene;bicyclo-(2,2,1)-hepta-2,5 diene; alkenyl, alkylidene, cycloalkenyl andcycloalkylidene norbornenes such as 5-methylene-2norbornene (MNB),5-ethylidene-2-norbornene, 5-(4-cyclopentenyl)-2-norbornene; and5-cyclohexylidene-2-norbornene.

Illustrative, non-limiting examples of the diene monomers coupled byZiegler copolymerization catalysts to prepare the nodular polymers ofthis invention are norbornadiene, vinyl norbornene and butenylnorbornene. Illustrative of the dienes coupled by cationiccross-linkable catalyst to prepare the nodular polymers are1,4-hexadiene, ENB, and dicylopentadiene. Illustrative of the dienescoupled by free radical catalysts are MNB, VNB, and 1,5-hexadiene.Additionally, olefin cross-linking agents may be used. Such agentsinclude sulfur dichloride, dusulfenyl halides, borane, dithioalkenes,and mixtures thereof. Of the non-conjugated dienes typically used toprepare these copolymers, dienes containing at least one of the doublebonds in a strained ring are preferred. The amount of diene (mol basis)in the diene-containing segment of the polymer could be from about 0.1%mole to 50%, with 1% to 30% being preferred. The most preferred range is2%-20%.

The average ethylene content of the polymer could be as low as about 10%on a weight basis. The preferred minimum is about 25%. A more preferredminimum is about 30%. The maximum ethylene content could be about 90% ona weight basis. The preferred maximum is about 85%, with the mostpreferred being about 80%. The ethylene content of the two segmentscomprising the polymer can be the same or different. If different, thepreferred composition range for each segment is the same as stated abovefor the whole polymer.

The molecular weight of copolymer made in accordance with the presentinvention can vary over a wide range. It is believed that the weightaverage molecular weight could be as low as about 2,000. The preferredminimum is about 10,000. The most preferred minimum is about 20,000. Itis believed that the maximum weight average molecular weight could be ashigh as about 12,000,000. The preferred maximum is about 1,000,000. Themost preferred maximum is about 750,000. The preferred minimum molecularweight for an ethylene-propylene copolymer chain segment is 2×10⁴. Forthe ethylene-propylene-non-conjugated diene chain segment the preferredminimum MW is 2×10³.

In one embodiment, the nodular copolymer is prepared by beginning thepolymerization of the poly co-(ethylene-proplene) which is permitted togrow to a molecular weight of several tens of thousands, e.g., 10,000 to50,000 number average molecular weight. The polymerization of thecopolymer will generally have proceeded to about 50% of the totalanticipated weight of polymer at the end of polymerization, morepreferably at least 70% of the total weight; at that point in time, thediene monomer, and optionally, a cationic catalyst if the diene issubject to cationically catalyzed coupling are introduced into thereactor with or without additional ethylene and propylene. With Zieglercopolymerizable dienes the polymer copolymerizes with the double bondsof the diene monomer to form the nodular polymers of this invention.This diolefin copolymerizes at the chain ends couling several chainsAlternatively, coupling agent may be added at the entrance to thetubular reactor with a part of the ethylene and alpha-olefin monomer,polymerization being carried out until nodules are formed and thecoupling agent is substantially converted; then additional ethylene andalpha-olefin are added to grow nodular polymers of this invention.

The olefinic chlorosilane and olefinic halide copolymers of the U.S.application Ser. No. 813.980 are also suitable for use with the blendsof this invention.

These copolymers may be statistical (random) or segmented copolymerscomprising ethylene, alpha-olefin, and halogen-containing monomer whichis an olefinic hydrocarbon chlorosilane or an olefinic halide. Thesegmented copolymer may be in nodular form. These copolymers may furtherbe in the form of graft and clock polymers formed from the copolymerchains. The olefinic chlorosilane has the formula

    SiRR'.sub.x Cl.sub.3-x

wherein x is in the range of 0-2, R is a Ziegler copolymerizable olefin,and R' is a hydrocarbon with 1-30 carbon atoms selected from the groupconsisting of saturated or saturated as well as branched or unbranchedaliphatic, aromatic, cyclic, and polycyclic hydrocarbons. R may furtherbe selected from the group consisting of norbornenyl, dicyclopentenyl,and 1-hexenyl. The chlorosilane may further be selected from the formula

    CH.sub.2 ═CH--(CRR').sub.n --SiR.sub.x Cl.sub.3-x

wherein x is in the range of 0-2, n is greater than or equal to 0, and Rand R' are the same or different, each being a hydrocarbon with 1-30carbon atoms selected from the group consisting of saturated orunsaturated as well as branched or unbranched aliphatic, aromatic,cyclic, and polycyclic hydrocarbons. In a preferred embodiment, thechlorosilane is selected from the group consisting of vinyl dimethylchlorosilane, vinyl ethyl dichlorosilane, 5-hexenyldimethylchlorosilane,5-hexenyltrichlorosilane, 7-octenyltrichlorosilane, and phenylallyldichlorosilane.

The olefinic hydrocarbon halide has the formula

    RR'X

wherein

(i) R is a Ziegler copolymerizable olefin;

(ii) R' is a hydrocarbon with 1-30 carbon atoms selected from a groupconsisting of the saturated or unsaturated as well as branched orunbranched aliphatic aromatic, cyclic, and polycyclic hydrocarbons; and

(iii) X is a halogen.

Then preferred olefinic hydrocarbon halides are 5-parachloromethylphenyl-2-norbonene and 5-chloromethyl-2-norbonene.

These copolymers are prepared by a polymerization process conducted:

(a) in at least one mix-free reactor,

(b) using a catalyst system that produces essentially one activecatalyst species,

(c) using at least one reaction mixture which is essentially transferagent-free, and

(d) in such a manner and under conditions sufficient to initiatepropagation of essentially all polymer chains simultaneously.

A tubular reactor is preferred for the process.

The composition of the copolymer is dependent upon the point at whichthe various reactants are added to the reactor. In a tubular reactor,the statistical polymer will result if the halogen-containing monomer isadded at the reactor inlet and is present along essentially the entire .length of the reactor. The segmented copolymer will result if thehalogen-containing monomer is instead added at one or more locationsites along the reactor with additional ethylene and alpha-olefinappropriately fed; the copolymer chains will bear second segmentscorresponding to such locations where the olefinic chlorosilane orolefinic hydrocarbon halide is added.

The copolymer chains can be cross-linked at their chlorosilane orolefinic halide functional groups. Where the third comound in thecopolymer is an olefinic chlorosilane, the cross-linking agent is wateror at least one polyfunctional proton donors. Where thehalogen-containing monomer is olefinic hydrocarbon halide, thecross-linking agent is zinc oxide or a polyfunctional nucleophile.

The structure of the resulting cross-linked copolymer is also dependentupon the sequence of monomers along the copolymer chains. Where theolefinic chlorosilane or olefinic hydrocarbon halide has been introducedat the reactor inlet, and the olefinic chlorosilane or olefinichydrocarbon halide is present throughout the chain, cross-linking willaccordingly occur throughout the chain. Where the olefinic chlorosilaneor olefinic hydrocarbon halide is rather introduced at one or morelocations along the reactor, at such addition rates which will cause theformation of copolymer chains having contiguous first and secondsegments of sufficient length, cross-linking will result in nodularregions of second segments with first segments extending therefrom.

Variations of such nodular copolymer products can be prepared by addingpolyfunctional proton donors or polyfunctional nucleophiles whichcontain additional functional groups. Examples of such functional groupsare amides, pyridines, polycaprolactones, pyrrolidone, imidazole,polycaprolactams, etc.

These copolymers can also be used to make block and graft polymers,including compatibiliserz and thermoplastic elastomers.

In one embodiment the copolymer chains are reacted with a metalatingagent, such as a branched alkyl lithium. An anionically polymerizablemonomer is then added, which polymerizes anionically to give chains ofthe monomer grafted onto the ethylene-alpha-olefin copolymer chains.

The halogen-containing monomer copolymers, upon mixing with certainplastics, will chemically link with such plastics through the olefinicchlorosilane or olefinic hydrocarbon halide.

Where the halogen-containing monomer is olefinic chlorosilane, thepolymer will react with polycarbonates, polyamides, polyesters,polyephenylene oxides, and acetals The plastic reacts with the polymerto form a silicon-plastic bond, releasing hydrogen from the plastic andhalogen from the olefinic chlorosilane.

Where the halogen-containing monomer is olefinic hydrocarbon halide, thecopolymer will react with polyamides (nylons). The NH₂ group of thepolyamide reacts with the olefinic-hydrocarbon halide. Here too,hydrogen is released from the plastic and halogen from thehalogen-containing monomer.

In another embodiment a cationic catalyst, such as a Lewis acid, isreacted with the hydrocarbon halogen functionality on the copolymerchains, and a cationically polymerizable monomer is then added to graftonto the copolymer chains.

Among the plastic compositions which can be used in the blend of thisinvention are thermoplastic compositions. Suitable thermoplasticcompositions include polypropylenes, polyethylenes, including highdensity polyethenes, low density polyethylenes, and linear low densitypolyethylenes, polystyrenes, polyvinyl chlorides, polycarbonates,polyamides (nylons), polyesters, polyphenylene oxides,ethylene/methylacrylate copolymers, polybutylenes, polyvinyl acetates,ethylene/vinyl acetate copolymers, polymethyl methacrylates,acrylonitrile-butadienne-styrenes, acetals, alkyds, acrylics, polyethylmethacrylates, and heteroblock propylene-ethylene copolymers.

Polypropylene, particularly that having greater than 90% hot heptaneinsolubles and melt flow rates of 0.2 to 100, especially 4 to 20 b/10minutes, are particularly preferred for use with the compositions ofthis invention.

One or more of such plastic compositions can be used together. Apreferred combination is that of polypropylene and polyethylene.

Additional suitable plastic compositions are heteroblockpropylene-ethylene copolymers. These copolymers, known in the art, areblock or random thermoplastic copolymers, as opposed to the Cozewith etal. elastomer compositions used in the blends of this invention. Theseblock copolymers contain at least 50% by weight polypropylene, and mayfurther be described as crystalline heteroblock copolymers having acrystalline melting point greater than 150° C.

These block copolymers may be prepared by means of a sequentialpolymerization In one such process, wherein the polypropylene isprepared in a first reactor and transmitted to a second reactor, whereinethylene and propylene are added to produce the copolymer. Examples ofreactions for making these block copolymers are shown in Holzer et al.,U.S. Pat. No. 3,262,992, and Castagna, U.S. Pat. No. 3,937,758.

At least 50% by weight of the polypropylene in these block copolymers ispresent as isotactic polypropylene, which provides the thermoplasticcharacter to these polymers.

The blends of this invention can also include fillers, stabilizers,antioxidants, processing aids, colorants, and other known additives, ifdesired, in conventional amounts.

Preferred plastic compositions for the blends of this invention arepolypropylene and heteroblock propylene-ethylene copolymer.Polyethylene, such as low density polyethylene (LDPE), linear lowdensity polyethylene (LLDPE), or high density polyethylene (HDPE) canfurther be included in the blend.

The blends of the invention may be prepared by any conventional means.The blending is generally conducted at a temperature above the meltingpoint of the plastic, usually at 150° C. or higher. Conventional mixingapparatus such a Banbury Batch Mixer, a Farrel Continuous Mixer, asingle screw extruder, or a double screw extruder may be employed.Kneading or roller milling of the blend may also be utilized.

The time required for mixing depends upon the quantity of components inthe blend and the type of mixing apparatus; generally, no more than afew minutes is required.

At the temperature and shear rate at which the blend is being produced,the rates of the viscosity of the elastomer of the invention to thevisco of the polypropylene should be less than approximately 4.0,preferably approximately 0.3 to approximately 3.0. This will give anintimate dispersion of the elastomer in the plastic.

For the purpose of obtaining the desired viscosity ratio, the viscosityof the elastomer and propylene at the shear rate and temperature of themixing apparatus can be estimated by a constant rate capillaryrheometer, such as the Monsanto Processability Tester (MPT).

With these data, it is therefore possible to select a suitablecombination of the two components such that the viscosity of theelastomer, under the appropriate temperature and shear rate conditions,is approximately 0.3 to 4.0 times, preferably approximately 0.3 to 3.0times, that of the polypropylene in which it is to be dispersed.

Subsequent to the blending step, the blends can be molded in anyconventional molding equipment, such as injection molding machines orextruders, utilizing molding cycles, temperatures, and pressures whichwill bring about the desired shape and thickness of the molded article.

Generally, injection molding may take place at temperatures in the rangeof approximately 174°-315° C. for 5-10 minutes or more, and injectinginto a room-temperature mold at 500 to 3,000 psi, depending upon thedesired shape and thickness of the molded article.

The elastomer of the blends of the invention, and the polyethylene, whenpresent, can be cured after blending, and during or prior to the moldingstep.

Curing may be performed by adding to the blend an amount of a curingagent, such as a free radical generating or crosslinking agent,sufficient to cause substantially complete crosslinking of thesecross-linkable components, and subjecting them to curing conditions,e.g., a temperature in the range of approximately 175°-205° C.

Organic peroxides are suitable for use as curing agents. Examples ofuseful organic peroxides include dicumal peroxide, di-tertiary butylperoxide, tert-butyl perbenzoate, bis (a,a-dimethylbenzyl) peroxide, 2,5-bis (tert.-butylperoxy)-2,5-dimethylhexane, a, a' bis(tert.-butylperoxy) diisopropylbenzene, and others containing tertiarycarbon groups, to name a few. Mixed peroxide-filler type curing systemsor packages may also be employed if desired, such as Vulcup R 40 KE,sold by Hercules Incorporated, which is comprised about 40 wt. %a,a-bis(t-butylperoxy) diisopropylbenzene on Burgess KE clay. Anotherexample of a suitable peroxide-filler cure package includes Dicup R 40KE, which contains 40 wt. % dicumyl peroxide on Burgess KE clay, alsosold by Hercules Incorporated.

Phenolic curatives and cure activators are also suitable as curingagents.

The particular amount of curing agent required to provide full curing iswell known in the art, and may be readily determined by reference toappropriate literature provided by Hercules Incorporated, Wilmington,Delaware. By way of example, an organic peroxide is generally used inamounts of from about 0.5 to about 4 parts, preferably from about 1 toabout 3 parts, per 100 parts of cross-linkable rubber and polyethylene.

Triallylcyanurate is preferably incorporated into the mixture prior tocuring, for the purpose of enhancing the curing and preventingdegradation of the plastic composition.

Where the plastic compositions of the blends of the invention comprisepolypropylene and polyethylene, the polypropylene generally comprises atapproximately 70-95% by weight of the blend; the polyethylene, 2-20%;the elastomer composition, 2-28%.

Where polypropylene and polyethylene are employed the elastomercompositions of the blends of the invention may be preblended with thepolyethylene prior to blending with the polypropylene.

When the composition of the invention comprises approximately 50% byweight or more, preferably up to approximately 80%, and, mostpreferably, up to approximately 75% by weight, of the elastomer, andapproximately 50% or less by weight poplypropylene, subjecting thecomposition to the previously disclosed curing step will result in aproduct known as a thermoplastic elastomer. Such a product exhibits boththermoplastic and elastomeric properties, i.e, the product will processlike a thermoplastic, but have physical properties like elastomers.Shaped articles can be formed from such a product by extrusion,injection molding or compression molding without requiringvulcanization.

The previously indicated elastomeric compositions disclosed in theCozewith et al. patent and related patents and applications can beemployed in the techniques discussed in Coran et al., U.S. Pat. No.4,130,535 and Abdou-Sabet et al., U.S. Pat. No. 4,311,628, thedisclosures of which are hereby incorporated by reference thereto, toprepare the thermoplastic elastomers of the invention.

Where the plastic composition of the blend of the invention is primarilypolypropylene comprising approximately 90% or more by weight of theblend, and the elastomer composition is primarily single mode narrow MWDcopolymer comprising approximately 10% or less by weight of the blend,the blend will comprise a continuous phase of the polypropylene with adiscontinuous phase of narrow MWD copolymer dispersed therein. As theproportion of narrow MWD copolymer in the blend is increased above 10%by weight of the blend, at some point the continuous-discontinuousphases configuration of the blend will transform into a cocontinuousphases configuration.

Where polyethylene is also present, and the polypropylene comprisesapproximately 85% or more by weight of the blend, with the single modenarrow MWD copolymer 5% or less and the single mode narrow MWD copolymercomprising approximately 10% or less by weight of the blend, the blendwill also assume a continuous-discontinuous phase configuration; thediscontinuous phase will be in the form of particles having an innerregion of polyethylene and an outer surface of narrow MWD copolymer.

The presence of the elastomer composition compatibilizes thepolyethylene and polypropylene by rendering the blending of these twoplastic compositions easier.

Various properties for certain narrow MWD copolymers suitable for usewith the blends of this invention are shown in Table I.

                  TABLE I                                                         ______________________________________                                        Characteristics of Copolymers                                                 Poly- Wt. %                  Wt. %                                            mer   Ethylene M (.sub.L 1 + 8, 127° C.)                                                            Diene.sup.1                                                                         M.sub.w                                                                             M.sub.w /M.sub.n                     ______________________________________                                        A     39.0     40            0     190,000                                                                             1.4                                  B     47.0     40            0     176,000                                                                             1.4                                  C     65.0     15            0     140,000                                                                             1.5                                  D     65.0     50            0     190,000                                                                             1.4                                  E     50.0     28            5.0   100,000                                                                             1.5                                  F     73.0       75.0        5.3   --    --                                   ______________________________________                                         .sup.1 5ethylidene-2-norbornene                                          

The composition and properties of two blends, both employing a 5 MFRpolypropylene homopolymer, one further employing an elastomer known inthe art and the other employing a narrow MWD copolymer of the invention,are listed in Table II.

                  TABLE II                                                        ______________________________________                                        Evaluation of Elastomer Blended                                               With a 5 MFR Polypropylene Homopolymer                                        Sample No.           1 (Control)                                                                             2                                              ______________________________________                                        Composition                                                                   Vistalon 503.sup.1 wt. % (grams)                                                                   10.05     --                                                                  (1273)                                                   Polymer B, wt. % (grams)                                                                           --        10.05                                                                         (1273)                                         Polyethylene.sup.2 wt. % (grams)                                                                   4.93 (624)                                                                              4.93 (624)                                     Polypropylene.sup.3 wt. % (kilograms)                                                              85.0 (10.8)                                                                             85.0 (10.8)                                    Irganox 1076, wt. % (grams)                                                                        0.02 (3)  0.02 (3)                                       Mechanical Properties                                                         Melt Flow Rate @ 230° C., g/10 min.                                                         4.3       4.8                                            Izod Impact Strength, ft.-lb./in.                                              21° C., notched                                                                            1.2       1.0                                            -18° C., notched                                                                            0.57      0.54                                           -30° C., unnotched                                                                          10.1      9.7                                            -30° C., unnotched knit line                                                                2.1       2.6                                            Gardner Impact Strength, in.-lb                                               -18° C.       135       138                                            -30° C.       112       126                                            Flexural Modulus, secant, psi × 10.sup.-3                                                    160.1     161.3                                          Tensile Strength @ break, psi                                                                      3678      3978                                           Knit line Tensile, psi                                                                             2385      2783                                           ______________________________________                                         .sup.1 Exxon Chemical Americas EPM: Mooney Viscosity (M.sub.L 1 + 8' @        127° C.) = 30; 49 wt % ethylene                                        .sup.2 0.3 MI, 0.95 g/cc density                                              .sup.3 Polypropylene MFR = 5                                             

The composition and properties of three blends, all employing a 12 MFRpolypropylene homopolymer while each of the other two employs a narrowMWD copolymer of the invention, are comparatively listed in Table III.

                                      TABLE III                                   __________________________________________________________________________    Evaluation of Elastomer Blended with                                          12 MFR Polypropylene Homopolymer                                                              3                                                             Sample No.      (Control)                                                                            4      5                                               __________________________________________________________________________    Composition                                                                   Vistalon 503.sup.1, wt. % (grams)                                                             6.7 (2010)                                                    Polymer A, wt. % (grams)                                                                      --     6.7 (2010)                                                                           --                                              Polymer B, wt. % (grams)                                                                      --     --     6.7 (2010)                                      Polyethylene.sup.2 wt. % (grams)                                                              3.28 (984)                                                                           3.28 (984)                                                                           3.28 (984)                                      Polypropylene.sup.3, wt. % (kg)                                                               90.0 (27)                                                                            90.0 (27)                                                                            90.0 (27)                                       Irganox 1076, wt. % (grams)                                                                   0.02 (6)                                                                             0.02 (6)                                                                             0.02 (6)                                        Mechanical Properties                                                         Melt Flow Rate @ 230° C.                                                               9.2    9.6    9.6                                             g/10 min.                                                                     Izod Impact Strength, ft.-lb./in.                                              21° C., notched                                                                       0.70   0.62   0.55                                            -18° C., notched                                                                       0.44   0.41   0.43                                            -30° C., unnotched                                                                     6.4    6.5    6.3                                             -30° C., unnotched knit line                                                           1.8    1.8    2.7                                             Gardner Impact Strength, in.-lb                                               -18° C.  71     83     80                                              -30° C.  45     78     74                                              Flexural Modulus, secant,                                                                     120.9  124.4  121.1                                           psi × 10.sup.-3                                                         Tensile Strength @ break-psi                                                                  4552   4680   4633                                            Knit line Tensile, psi                                                                        2622   2785   3655                                            __________________________________________________________________________     .sup.1 Exxon Chemical Americas EPM: Mooney Viscosity (M.sub.L 1 + 8' @        127° C.) = 30; 49 wt % ethylene                                        .sup.2 0.3 MI, 0.95 g/cc density                                              .sup.3 Polypropylene MFR = 12                                            

The composition and properties of 5 additional blends, all employing a15 MFR polypropylene homopolymer, one further employing an elastomerknown in the art and the others each further employing a narrow MWDcopolymer of the invention, are comparatively listed in Table IV.

                                      TABLE IV                                    __________________________________________________________________________    Evaluation of Elastomer Blended with                                          15 MFR Polypropylene Homopolymer                                                              6                                                             Sample No.      (Control)                                                                            7      8      9      10                                __________________________________________________________________________    Composition                                                                   Vistalon 503.sup.1 wt. % (kg)                                                                 10.05 (8.5)                                                                          --     --     --     --                                Polymer B, wt. % (kg)                                                                         --     10.05 (8.5)                                                                          --     --     --                                Polymer C, wt. % (kg)                                                                         --     --     10.05 (8.5)                                                                          --     --                                Polymer D, wt. % (kg)                                                                         --     --     --     10.05 (8.5)                                                                          --                                Polymer E, wt. % (kg)                                                                         --     --     --     --     10.05 (8.5)                       Polyethylene.sup.2 wt. %                                                                      4.93   4.93   4.93   4.93   4.93                              (kg)            (4.18) (4.18) (4.18) (4.18) (4.18)                            Polypropylene.sup.3 wt. % (kg)                                                                85.0   85.0   85.0   85.0   85.0                              (kg)            (72.0) (72.0) (72.0) (72.0) (72.0)                            Irganox 1076, wt. %                                                                           0.02   0.02   0.02   0.02   0.02                              (kg)            (0.02) (0.02) (0.02) (0.02) (0.02)                            Mechanical Properties                                                         Melt Flow Rate @ 230° C.                                                               10.9   10.5   14.9   10.6   11.5                              g/10 min.                                                                     Izod Impact Strength, ft.-lb./in.                                              21° C., notched                                                                       0.76   0.77   0.63   0.65   0.76                              -18° C., notched                                                                       0.44   0.54   0.34   0.35   0.53                              -30° C., unnotched                                                                     6.0    6.9    4.8    4.2    7.8                               -30° C., unnotched knit line                                                           1.8    2.7    3.1    2.2    2.2                               Gardner Impact Strength, in.-lb                                               -18° C.  62     88     15     30     146                               -30° C.  56     66     8      18     121                               Flexural Modulus secant,                                                                      168.9  174.3  162.3  187.5  175.1                             psi × 10.sup.-3                                                         Ten. Strength @ break, psi                                                                    2367   2419   1890   2744   2383                              Knit line Tensile, psi                                                                        3320   3410   2052   3620   2540                              __________________________________________________________________________     .sup.1 Exxon Chemical American EPM: Mooney Viscosity (M.sub.L 1 + 8' @        127° C.) = 30; 49 st % ethylene                                        .sup.2 0.3 MI, 0.95 g/cc density                                              .sup.3 Polypropylene = 15 MFR                                            

                                      TABLE V                                     __________________________________________________________________________    Evaluation of Narrow MWD copolymer in Thermoplastic                           Olefin (TPO) Formulations                                                     Sample No.     11     12     13     14     15                                 __________________________________________________________________________    Composition                                                                   Vistalon 503.sup.1 wt. % (g)                                                                 25.0 (375)                                                                           --     --     --     --                                 Vistalon 7000.sup.2 wt. % (g)                                                                --     25.0 (375)                                                                           --     --     --                                 Polymer F, wt. % (g)                                                                         --     --     25.0 (375)                                                                           --     --                                 Polymer C, wt. % (g)                                                                         --     --     --     25.0 (375)                                                                           --                                 Polymer D, wt. % (g)                                                                         --     --     --     --     25.0 (375)                         Polypropylene,.sup.3 wt. %                                                                   74.8   74.8   74.8   74.8   7.48                               (g)            (1122) (1122) (1122) (1122) (1122)                             Irganox 1076, wt. % (g)                                                                      0.2 (3)                                                                              0.2 (3)                                                                              0.2 (3)                                                                              0.2 (3)                                                                              0.2 (3)                            Mechanical Properties                                                         Melt Flow Rate @ 230° C.,                                                             3.55   2.45   2.54   4.51   3.80                               g/10 min                                                                      Spiral Flow.sup.4, cm                                                                        15.6   14.6   12.5   15.2   14.8                               Izod Impact Strength, ft-lb/in                                                 21°  C., notched                                                                     10.1   7.9    2.0    4.0    7.3                                -20° C., unnotched                                                                    28.4   24.9   21.1   13.8   15.0                               -30° C., unnotched                                                                    --     --     16.3   12.9   13.7                               -40° C., unnotched                                                                    --     --     10.3   9.0    11.0                               Ten. Strength @ Break-psi                                                                    2510   2510   1920   2220   2330                               Enlongation @ Break, %                                                                       300    290    145    210    170                                Flexural Modulus,                                                                            120    125    129    116    120                                psi × 10.sup.-3                                                         __________________________________________________________________________     .sup.1 Exxon Chemical Americas EPM: Mooney Viscosity (M.sub.L 1 + 8' @        127° C.) = 30; 49 wt. % ethylene                                       .sup.2 Exxon Chemical Americas EPDM: Mooney Viscosity (M.sub.L 1 + 8' @       127° C.) = 55; 70 wt. % ethylene; 5 wt. % ENB                          .sup.3 Polypropylene MFR = 5.0                                                .sup.4 Nonstandard test for comparison purposes; higher values indicate       better mold filling characteristics. Conditions using Boy laboratory          injection press: Pressure = 800 psi; barrel temperature 230° C.;       nozzle temperature 267° C.; mold at 53° C.; 13 second           injection; 20 second hold                                                

                                      TABLE VI                                    __________________________________________________________________________    Thermoplastic Olefins (TPO's) Containing                                      Marrow MWD Copolymer Plus Talc                                                Sample No.        16     17     18                                            __________________________________________________________________________    Composition                                                                   Polymer C, wt. % (g)                                                                            31.0 (465)                                                                           30.0 (450)                                                                           28.0 (420)                                    Mistron Vapor, wt. % (g)                                                                        5.0 (75)                                                                             10.0 (150)                                                                           15 (225)                                      Heteroblock propylene-ethylene co-                                                              63.8 (957)                                                                           59.8 (897)                                                                           56.8 (852)                                    polymer.sup.1 wt. % (g)                                                       Irganox 1076 wt. % (g)                                                                          0.2 (3)                                                                              0.2 (3)                                                                               0.2 (3)                                      __________________________________________________________________________     .sup.1 Hetero block propyleneethylene copolymer is a 15 MFR polymer           containing 88 percent by weight of a polypropylene block and 12 percent b     weight of a postblock of a copolymer of ethylene and propylene, the           postblock containing 40 weight percent ethylene.                         

The following examples more particularly illustrate the nature of theinvention but are not intended to be limitative thereof. In thefollowing examples, the mechanical property evaluations were madeemploying the following tests.

    ______________________________________                                        TEST FOR    VIA            ASTM                                               ______________________________________                                        Melt Processability                                                                       MFR            D1238 L                                            Stiffness   Flexural Modulus                                                                             D790 I.A.                                          Stiffness Properties                                                                      Tensile & Elongation                                                                         D638                                                           at yield and break                                                Impact Strength                                                                           Notched Izod   D256, Method A                                                 Unnotched Izod D256, Method A                                                 Gardner Impact D3029                                              ______________________________________                                    

Test specimens for measuring the above mechanical properties wereproduced on a Watson Stillman Injection Molding Machine.

EXAMPLE 1

Two impact propylene blends were made and compared for impact propertiesand knit line strength. One blend was prepared with a commerciallyavailable ethylene propylene copolymer (Vistalon 503) having a MWD of4.5. The other was prepared With Polymer B of Table II.

Each blend was prepared by initially mixing the copolymer and HDPE in aBanbury Mixer for 4 minutes at a temperature of about 200° C. Thecopolymer/HDPE mixture was then pelletized and mixed with apolypropylene homopolymer in a Banbury Mixer for about 4 minutes atapproximately 200°. The mechanical properties of the 2 blends are alsoset forth in Table II.

The results of Table II illustrate that incorporation of a narrow MWDethylene-propylene copolymer in a 5 MFR polypropylene blend providesimproved knit line properties while maintaining all other propertiesapproximately constant.

EXAMPLE 2

Impact polypropylene copolymer blends were prepared with narrow MWDcopolymers in accordance with the formulations set forth in Table III.For purposes of comparison, an impact polypropylene blend was preparedwith Vistalon 503, a commercially available copolymer having a MWD of4.5.

Each of the blends was prepared by initially mixing the copolymer andHDPE in a Banbury Mixer for 4 minutes at a temperature of about 200° C.Each copolymer/HDPE mixture was then cooled and chopped in smallsquares.

The final impact copolymer blend was prepared by mixing thecopolymer/HDPE mixture with a polypropylene homopolymer in a 2.5 inchRoyle extruder. The die temperature of the extruder was approximately200° C. The mechanical properties of these blends are set forth in TableIII.

As illustrated, the blends containing the narrow MWD copolymer hadimproved impact and knit line properties.

EXAMPLE 3

Impact copolymer blends were prepared with narrow MWD copolymers inaccordance with the formulations set forth in Table IV. As in example 2,one blend was prepared with Vistalon 503 for comparison purposes.

Each of the blends was prepared in accordance with the procedure setforth in Example 2. The mechanical properties of the blends are setforth in Table IV.

As with the narrow MWD blends of Example 2, Samples 7 and 10 had betterimpact properties than the Vistalon 503 blend, Sample 6. Furthermore,Sample 8 had better Izod knit line properties than the control, butlower Gardner impact properties.

EXAMPLES 4

Five thermoplastic olefins (TPO) were made and compared for mechanicalproperties For comparison purposes, two of the blends were prepared withcommercially available EPM/EPDM elastomers.

Each blend was prepared by mixing the copolymer and polypropylenehomopolymer in a Banbury mixer for about 4 minutes at approximately 200°C. After completing mixing, the copolymer-polypropylene blend was cooledand granulated. The mechanical properties and polymer components of allthe TPO blends prepared are set forth in Table V.

EXAMPLE A

Three thermoplastic olefins (TPO) are made in accordance with theformulations set forth in Table VI. Each blend is prepared by mixing theheteroblock propylene-ethylene block copolymer, mistron vapor and narrowMWS copolymer in a Banbury mixer for about 4 minutes at approximately200° C. After completing mixing, the blend is cooled and granulated.

EXAMPLE B

A moderately filled flexible compound for extrusion, molding andthermoforming applications is prepared in accordance with theformulation below:

    ______________________________________                                        Polymer C.sup.1     23 wt. %  (345 grams)                                     Ethylene/Vinyl Acetate Copolymer                                                                  36 wt. %  (540 grams)                                     Flexon 766 oil      10 wt. %  (150 grams)                                     Atomite - C Co.sub.3                                                                              30 wt. %  (450 grams)                                     Stearic Acid        0.6 wt. % (9 grams)                                       Irganox 1076        0.4 wt. % (6 grams)                                       ______________________________________                                         .sup.1 2.5 MI; 19% VA                                                    

The blend is prepared by mixing Polymer C, ethylene/vinyl acetatecopolymer, Flexon 766 oil and atomite in a Banbury mixer at high rotorspeed until flux (approximately 2 minutes). After flux, the blend ismixed for another 3 minutes at low rotor speed. Next, the stearic acidand Irganox 1076 are added to the blend, and the blen is mixed foranother minute at low rotor speed. Finally, the blend is dumped, cooledand granulated.

EXAMPLE C

An impact polypropylene blend is made by blending 3.4 wt. % (51 grams)of Polymer C, 1.7 wt. % (26 grams) of a 0.3 MI HDPE, 0.8 wt. % (12grams) of Irganox 1076 and 94.1 wt. % (1424 grams) of a 4 MFR heterblockpropylene ethylene copolymer containing 90 percent by weight of apolypropylene block and 10 percent by weight of a postblock of acopolymer of ethylene and propylene, the postblock containing 40 weightpercent ethylene in a Banbury mixer for 4 minutes at 200° C. Aftercompleting mixing, the blend is cooled and granulated.

EXAMPLE D

A thermoplastic olefin (TPO) is prepared by mixing 49.5 wt. % (750grams) of Polymer C, 9.9 wt. % (150 grams) of Sunpar 2280 oil, 0.99 wt.% (15 grams) of Irganox 1010 and 39.6 wt. % (600 grams) of a 4 MFRheteroblock propylene ethylene copolymer containing 88 percent by weightof a polypropylene block and 12 percent by weight of a postblock of acopolymer of ethylene and propylene, the postblock containing 40 weightpercent ethylene, for approximately 4 minutes in a Banbury mixer at 200°C. After completing mixing, the blend is cooled and granulated.

EXAMPLE E

A thermoplastic elastomer is prepared in accordance with the formulationshown below:

    ______________________________________                                        Polymer E          750 grams (50 wt. %)                                       Profax 6823PP (0.4 MFR)                                                                          251 grams (16.7 wt. %)                                     Nucap 190 Clay     159 grams (10.6 wt. %)                                     Titanium Dioxide    21 grams (1.4 wt. %)                                      Sun-0-Lite 127      21 grams (1.4 wt. %)                                      Sunpar 150 oil     239 grams (15.9 wt. %)                                     SP 1045 Resin       44 grams (2.9 wt. %)                                      ZnO                 9 grams (0.6 wt. %)                                       Stannous Chloride   7.5 grams (0.5 wt. %)                                     ______________________________________                                    

The blend is prepared by mixing Polymer E, Profax 6823 PP, Nucap 190Clay, Titanium Dioxide, and Sun-O-Lite 127 in a Banbury Mixer at highrotor speed until flux (about 2 minutes). After flux, 119.5 grams of theoil is added and the blend is mixed for 1 minute. Next, the remainder ofthe oil is added and the blend is mixed for another minute. With the oilin the blend, the SP 1045 Resin is added and mixed for 20 seconds. Then,the ZnO and stannous chloride are added and the blend is mixed for 6minutes at a low rotor speed. (Temperature is about 200°). Finally, theblend is dumped, cooled and granulated.

EXAMPLE F

A thermoplastic elastomer is prepared in accordance with the formulationshown below:

    ______________________________________                                        Polymer E          860 grams (57.3 wt. %)                                     Profax 6823PP (0.4 MFR)                                                                          251 grams (16.7 wt. %)                                     Nucap 190 Clay     159 grams (10.6 wt. %)                                     Titanium Dioxide    21 grams (1.4 wt. %)                                      Sun-0-Lite 127      21 grams (1.4 wt. %)                                      Sunpar 150 oil     129 grams (8.6 wt. %)                                      SP 1045 Resin       44 grams (2.9 wt. %)                                      ZnO                 9 grams (0.6 wt. %)                                       stannous chloride   7.5 grams (0.5 wt. %)                                     ______________________________________                                    

The blend is prepared by mixing Polymer E, Profax 6823 PP, Nucap 190Clay, Titanium Dioxide, and Sun-O-Lite 127 in a Banbury Mixer at highrotor speed until flux (about 2 minutes). After flux, the oil is addedthe blend is mixed for 1 minute. Next, the SP 1045 resin is added andthe blend is mixed for another 20 seconds. Then, the ZnO and StannousChloride are added and the blend is mixed for 6 minutes at a low rotorspeed. (Temperature is about 200°.) Finally, the blend is dumped, cooledand granulated.

What is claimed is:
 1. A composition comprising:(a) at least oneelastomer copolymer comprising ethylene and at least one other alphaolefin, having a weight average molecular weight of at least 20,000 andhaving at least one of M_(w) /M_(n) less than 2 and M_(z) /M_(w) lessthan 1.8, wherein at least two portions of essentially each copolymerchain of said copolymer, each portion comprising at least 5 wt. % of thechain, differ in composition from one another by at least about 5 wt. %ethylene; (b) a first plastic composition different from said firstplastic composition; and (c) a second plastic composition.
 2. Thecomposition as defined by claim 1 wherein said first plastic compositionis polypropylene, and said second plastic composition is polyethylene.3. The composition as defined by claim 1 comprising:(a) a continuousphase comprising said first plastic composition; and (b) a discontinuousphase comprising said second plastic composition and said at least onecopolymer, said discontinuous phase being dispersed within saidcontinuous phase.
 4. The composition as defined by claim 3 wherein saidfirst plastic composition is polypropylene and said second plasticcomposition is polyethylene.
 5. The composition as defined by claim 3wherein said discontinuous phase comprises particles, substantially eachof said particles comprising an inner region of said second plasticcomposition and an outer region of said at least one copolymer.
 6. Thecomposition as defined by claim 1 wherein said first plastic compositionis polypropylene said second plastic composition is polyethylene, andsaid at least one copolymer is at least one member selected from thegroup consisting ethylene-propylene copolymer and ethylene-propyleneterpolymer.
 7. The composition as defined by claim 6 wherein saidpolypropylene comprises at least approximately 85 wt. % of the blend,said polyethylene comprises approximately 5 wt. % or less by weight ofthe blend, and said at least one copolymer comprises approximately 10wt. % or less of the blend.
 8. The composition as defined by claim 1,wherein said at least one copolymer is an ethylene propylene terpolymer.9. The composition as defined by claim 8 wherein said ethylene propyleneterpolymer comprises ethylene propylene and a non-conjugated dieneselected from a group consisting of ethylidene norbornene,1,4-hexadiene, dicyclopentadiene, vinyl norbornene, methylenenorbornene, and mixtures thereof.